Edition 1997-04-01
Published by

Siemens AG,

Bereich Halbleiter, Marketing-
Kommunikation, Balanstraße 73,
81541 München

Siemens AG 1997.

Attention please!

As far as patents or other rights of third parties are concerned, liability is only assumed for components, not for applications, processes
and circuits implemented within components or assemblies.
The information describes the type of component and shall not be considered as assured characteristics.
Terms of delivery and rights to change design reserved.
For questions on technology, delivery and prices please contact the Semiconductor Group Offices in Germany or the Siemens Companies
and Representatives worldwide (see address list).
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your nearest Siemens Office, Semiconductor Group.
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Critical components

of the Semiconductor Group of Siemens AG, may only be used in life-support devices or systems

with the express

written approval of the Semiconductor Group of Siemens AG.
1 A critical component is a component used in a life-support device or system whose failure can reasonably be expected to cause the

failure of that life-support device or system, or to affect its safety or effectiveness of that device or system.

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man life. If they fail, it is reasonable to assume that the health of the user may be endangered.

C501 Data Sheet
Revision History :

1997-04-01

Previous Releases :

11.92, 11.93, 08.94, 08.95, 10.96

Page
(previous
version)

Page
(new
version)

Subjects (changes since last revision)

general

C501G-1E OTP version included

4
5
5-7
11
8, 9, 10

13
14
-
15-18
17
-
-
41
-

4
5
5-7
11
8, 9, 10

13
14
15
16-18
17
25-28
31
41
43, 44

Ordering information resorted and C501G-1E types added
Table with literature hints added
Pin configuration logic symbol for pins EA/Vpp and ALE/PROG updated
Pin description for ALE/PROG and EA/Vpp completed
Port 1, 3, 2 pin description: "bidirectional" replaced by "quasi-
bidirectional"
Block diagram updated for C501G-1E
New design of register (PSW) description
"Memory organization" added
Actualized design of the SFR tables
Reset value of T2CON corrected
Description for the C501-1E OTP version added
DC characteristics for C501-1E added
Timing "External Clock Drive" now behind "Data Memory Cycle"
AC characteristics for C501-1E added

C501

Semiconductor Group

1997-04-01

8-Bit CMOS Microcontroller

Preliminary

C501

Fully compatible to standard 8051 microcontroller

Versions for 12/24/40 MHz operating frequency

Program memory : completely external (C501-L)

8 ROM (C501-1R)

8 OTP memory (C501-1E)

256

8 RAM

Four 8-bit ports

Three 16-bit timers / counters (timer 2 with up/down counter feature)

USART

Six interrupt sources, two priority levels

Power saving modes

Quick Pulse programming algorithm (C501-1E only)

2-Level program memory lock (C501-1E only)

P-DIP-40, P-LCC-44, and P-MQFP-44 package

Temperature ranges :

SAB-C501

: 0

°C to 70

°C

SAF-C501

: 40

°C to 85

°C

Figure 1
C501G Functional Units

MCA03238

Port 0

Port 1

Port 2

Port 3

RAM

256 x 8

CPU

USART

Power

Saving

8K x 8 OTP (C501-1E)

Modes

8K x 8 ROM (C501-1R)

C501

Semiconductor Group

1997-04-01

The C501-1R contains a non-volatile 8K

8 read-only program memory, a volatile 256

8 read/

write data memory, four ports, three 16-bit timers counters, a seven source, two priority level
interrupt structure and a serial port. The C501-L is identical, except that it lacks the program
memory on chip. The C501-1E contains a one-time programmable (OTP) program memory on chip.
The term C501 refers to all versions within this specification unless otherwise noted. Further, the
term C501 refers to all versions which are available in the different temperature ranges, marked with
SAB-C501... or SAF-C501....

Ordering Information

Type

Ordering Code Package

Description
(8-Bit CMOS microcontroller)

SAB-C501G-LN
SAB-C501G-LP
SAB-C501G-LM

Q67120-C969
Q67120-C968
Q67127-C970

P-LCC-44
P-DIP-40
P-MQFP-44

for external memory (12 MHz)

SAB-C501G-L24N
SAB-C501G-L24P
SAB-C501G-L24M

Q67120-C1001
Q67120-C999
Q67127-C1014

P-LCC-44
P-DIP-40
P-MQFP-44

for external memory (24 MHz)

SAB-C501G-L40N
SAB-C501G-L40P
SAB-C501G-L40M

Q67120-C1002
Q67120-C1000
Q67127-C1009

P-LCC-44
P-DIP-40
P-MQFP-44

for external memory (40 MHz)

SAF-C501G-L24N
SAF-C501G-L24P

Q67120-C1011
Q67120-C1010

P-LCC-44
P-MQFP-44

for external memory (24 MHz)
ext. temp. 40 °C to 85 °C

SAB-C501G-1RN
SAB-C501G-1RP
SAB-C501G-1RM

Q67120-DXXX
Q67120-DXXX
Q67127-DXXX

P-LCC-44
P-DIP-40
P-MQFP-44

with mask-programmable ROM (12 MHz)

SAB-C501G-1R24N
SAB-C501G-1R24P
SAB-C501G-1R24M

Q67120-DXXX
Q67120-DXXX
Q67127-DXXX

P-LCC-44
P-DIP-40
P-MQFP-44

with mask-programmable ROM (24 MHz)

SAB-C501G-1R40N
SAB-C501G-1R40P
SAB-C501G-1R40M

Q67120-DXXX
Q67120-DXXX
Q67127-DXXX

P-LCC-44
P-DIP-40
P-MQFP-44

with mask-programmable ROM (40 MHz)

SAF-C501G-1R24N
SAF-C501G-1R24P

Q67120-DXXX
Q67120-DXXX

P-LCC-44
P-DIP-40

with mask-programmable ROM (24 MHz)
ext. temp. 40 °C to 85 °C

SAB-C501G-1EN
SAB-C501G-1EP

Q67120-C1054
Q67120-C1056

P-LCC-44
P-DIP-40

with OTP memory (12 MHz)

SAF-C501G-1EN
SAF-C501G-1EP

Q67120-C2002
Q67120-C2003

P-LCC-44
P-DIP-40

with OTP memory (12 MHz))
ext. temp. 40

°C to 85

°C

SAB-C501G-1E24N
SAB-C501G-1E24P

Q67120-C2005
Q67120-C2006

P-LCC-44
P-DIP-40

with OTP memory (24 MHz)

SAF-C501G-1E24N
SAF-C501G-1E24P

Q67120-C2008
Q67120-C2009

P-LCC-44
P-DIP-40

with OTP memory (24 MHz))
ext. temp. 40

°C to 85

°C

Semiconductor Group

1997-04-01

C501

Note:

Versions for extended temperature range 40

°C to 110

°C (SAH-C501G) on request.

The ordering number of ROM types (DXXX extensions) is defined after program release
(verification) of the customer.

Additional Literature

For further information about the C501 the following literature is available :

Figure 2
Pin Configuration P-LCC-44 Package (Top view)

Title

Ordering Number

C501 8-Bit CMOS Microcontroller User's Manual

B158-H6723-X-X-7600

C500 Microcontroller Family
Architecture and Instruction Set User's Manual

B158-H6987-X-X-7600

C500 Microcontroller Family - Pocket Guide

B158-H6986-X-X-7600

MCP03214

1 44 43 42 41 40

P1.5

P1.6

P1.7

RxD/P3.0

N.C.

TxD/P3.1

INT0/P3.2

INT1/P3.3

T0/P3.4

T1/P3.5

WR/P3.6

RD/P3.7

XTAL2

XTAL1

P2.0/A8

P2.1/A9

P2.2/A10

P2.3/A11

P2.5/A13

P2.6/A14

P2.7/A15

PSEN

ALE/PROG

EA/

P0.6/AD6

P0.5/AD5

P0.4/AD4

P0.3/AD3

P0.2/AD2

P0.1/AD1

P0.0/AD0

N.C

P1.3

P1.4

C501

N.C.

RESET

P0.7/AD7

P1.2

P1.0/T2

P1.1/T2EX

P2.4/A12

N.C.

C501

Semiconductor Group

1997-04-01

Figure 3
Pin Configuration P-DIP-40 Package

(top view)

MCP03215

XTAL1

XTAL2

P2.5/A13

P1.7

P0.7/AD7

RESET

RxD/P3.0

ALE/PROG

PSEN

P2.7/A15

P2.6/A14

T0/P3.4

T1/P3.5

P2.4/A12

WR/P3.6

P2.3/A11

P2.2/A10

P2.1/A9

P2.0/A8

P1.3

P1.2

T2EX/P1.1

P0.4/AD4

P0.3/AD3

P0.1/AD1

C501

RD/P3.7

TxD/P3.1

INT1/P3.3

INT0/P3.2

P1.4

P1.5

P1.6

T2/P1.0

P0.0/AD0

P0.2/AD2

P0.6/AD6

P0.5/AD5

EA/

Semiconductor Group

1997-04-01

C501

Figure 4
Pin Configuration P-MQFP-44 Package

(top view)

Figure 5
Logic Symbol

MCP03216

P1.5

P1.6

P1.7

RxD/P3.0

N.C.

TxD/P3.1

INT0/P3.2

INT1/P3.3

T0/P3.4

T1/P3.5

P2.5/A13

P2.6/A14

P2.7/A15

PSEN

ALE/PROG

EA/

P0.6/AD6

P0.5/AD5

P0.4/AD4

RESET

P0.7/AD7

C501

N.C.

P0.3/AD3
P0.2/AD2

P0.1/AD1

P0.0/AD0

N.C.

P1.0/T2

P1.1/T2EX

P1.2
P1.3
P1.4

WR/P3.6

RD/P3.7

XTAL2

XTAL1

N.C.

P2.0/A8

P2.1/A9

P2.2/A10

P2.3/A11

P2.4/A12

MCL03217

8-Bit Digital

C501

Port 0

Port 1

8-Bit Digital

Port 2

8-Bit Digital

Port 3

8-Bit Digital

XTAL1
XTAL2

RESET

ALE/PROG

PSEN

C501

Semiconductor Group

1997-04-01

Table 1
Pin Definitions and Functions

Symbol

Pin Number

I/O*) Function

P-LCC-44 P-DIP-40 P-MQFP-44

P1.0 P1.7 29

2
3

1
2

4044,
13,

40
41

I/O

Port 1

is a quasi-bidirectional I/O port with
internal pull-up resistors. Port 1 pins that
have 1s written to them are pulled high by
the internal pullup resistors, and in that
state can be used as inputs. As inputs,
port 1 pins being externally pulled low will
source current (

, in the DC character-

istics) because of the internal pull-up
resistors. Port 1 also contains the timer 2
pins as secondary function. The output
latch corresponding to a secondary
function must be pro-grammed to a one
(1) for that function to operate.
The secondary functions are assigned to
the pins of port 1, as follows:
P1.0

Input to counter 2

P1.1

T2EX Capture - Reload trigger of

timer 2 / Up-Down count

*) I

= Input

O = Output

Semiconductor Group

1997-04-01

C501

P3.0 P3.7 11,

1319

16
17
18

1017

14
15
16

5, 713

10
11
12

I/O

Port 3

is a quasi-bidirectional I/O port with
internal pull-up resistors. Port 3 pins that
have 1s written to them are pulled high by
the internal pull-up resistors, and in that
state they can be used as inputs. As
inputs, port 3 pins being externally pulled
low will source current (

, in the DC

characteristics) because of the internal
pull-up resistors. Port 3 also contains the
interrupt, timer, serial port 0 and external
memory strobe pins which are used by
various options. The output latch
corresponding to a secondary function
must be programmed to a one (1) for that
function to operate.
The secondary functions are assigned to
the pins of port 3, as follows:
P3.0

receiver data input (asyn-
chronous) or data input
output (synchronous) of
serial interface 0

P3.1

transmitter data output
(asynchronous) or clock
output (synchronous) of
the serial interface 0

P3.2

INT0

interrupt 0 input/timer 0
gate control

P3.3

INT1

interrupt 1 input/timer 1
gate control

P3.4

counter 0 input

P3.5

counter 1 input

P3.6

the write control signal lat-
ches the data byte from
port 0 into the external
data memory

P3.7

the read control signal
enables the external data
memory to port 0

*) I

= Input

O = Output

Table 1
Pin Definitions and Functions

(cont'd)

Symbol

Pin Number

I/O*) Function

P-LCC-44 P-DIP-40 P-MQFP-44

C501

Semiconductor Group

1997-04-01

XTAL2

XTAL2

Output of the inverting oscillator
amplifier.

XTAL1

XTAL1

Input to the inverting oscillator amplifier
and input to the internal clock generator
circuits.
To drive the device from an external
clock source, XTAL1 should be driven,
while XTAL2 is left unconnected. There
are no requirements on the duty cycle of
the external clock signal, since the input
to the internal clocking circuitry is divided
down by a divide-by-two flip-flop.
Minimum and maximum high and low
times as well as rise fall times specified
in the AC characteristics must be
observed.

P2.0 P2.7 2431

2128

1825

I/O

Port 2

is a quasi-bidirectional I/O port with
internal pull-up resistors. Port 2 pins that
have 1s written to them are pulled high
by the internal pull-up resistors, and in
that state they can be used as inputs. As
inputs, port 2 pins being externally pulled
low will source current (

, in the DC

characteristics) because of the internal
pull-up resistors. Port 2 emits the high-
order address byte during fetches from
external program memory and during
accesses to external data memory that
use 16-bit addresses (MOVX @DPTR).
In this application it uses strong internal
pull-up resistors when issuing 1s. During
accesses to external data memory that
use 8-bit addresses (MOVX @Ri), port
2 issues the contents of the P2 special
function register.

*) I

= Input

O = Output

Table 1
Pin Definitions and Functions

(cont'd)

Symbol

Pin Number

I/O*) Function

P-LCC-44 P-DIP-40 P-MQFP-44

Semiconductor Group

1997-04-01

C501

PSEN

The Program Store Enable

output is a control signal that enables the
external program memory to the bus
during external fetch operations. It is
activated every six oscillator periods
except during external data memory
accesses. Remains high during internal
program execution.

RESET

RESET

A high level on this pin for two machine
cycles while the oscillator is running
resets the device. An internal diffused
resistor to

permits power-on reset

using only an external capacitor to

ALE/PROG 33

I/O

The

Address Latch Enable

output is used for latching the low-byte of
the address into external memory during
normal operation. It is activated every six
oscillator periods except during an
external data memory access.
For the C501-1E this pin is also the
program pulse input (PROG) during OTP
memory programming.

EA/

External Access Enable

When held at high level, instructions are
fetched from the internal ROM (C501-1R
and C501-1E) when the PC is less than
2000H. When held at low level, the C501
fetches all instructions from external
program memory. For the C501-L this
pin must be tied low.
This pin also receives the programming
supply voltage

during OTP memory

programming (C501-1E) only).

*) I

= Input

O = Output

Table 1
Pin Definitions and Functions (cont'd)

Symbol

Pin Number

I/O*) Function

P-LCC-44 P-DIP-40 P-MQFP-44

C501

Semiconductor Group

1997-04-01

P0.0 P0.7 4336

3932

3730

I/O

Port 0
is an 8-bit open-drain bidirectional I/O
port. Port 0 pins that have 1s written to
them float, and in that state can be used
as high-impedance inputs. Port 0 is also
the multiplexed low-order address and
data bus during accesses to external
program or data memory. In this
application it uses strong internal pull-up
resistors when issuing 1s.
Port 0 also outputs the code bytes during
program verification in the C501-1R and
C501-1E. External pull-up resistors are
required during program verification.

Circuit ground potential

Supply terminal for all operating modes

N.C.

1, 12,
23, 34

6, 17,
28, 39

No connection

*) I

= Input

O = Output

Table 1
Pin Definitions and Functions (cont'd)

Symbol

Pin Number

I/O*) Function

P-LCC-44 P-DIP-40 P-MQFP-44

Semiconductor Group

1997-04-01

C501

Functional Description

The C501 is fully compatible to the standard 8051 microcontroller family.

It is compatible with the 80C32/52/82C52. While maintaining all architectural and operational
characteristics of the 8051microcontroller family, the C501 incorporates some enhancements in the
timer 2 unit.

Figure 6 shows a block diagram of the C501.

Figure 6
Block Diagram of the C501

Port 3

Port 2

Port 1

8-Bit Digit.

Port 0

RAM

RESET

ALE/PROG

PSEN

EA/

MCB03219

XTAL2

OSC & Timing

CPU

Timer 0

Timer 1

Timer 2

Interrupt Unit

Serial Channel

(USART)

C501

XTAL1

256 x 8

C501-1R : ROM

C501-1E : OTP

8K x 8

8-Bit Digit.

C501

Semiconductor Group

1997-04-01

CPU

The C501 is efficient both as a controller and as an arithmetic processor. It has extensive facilities
for binary and BCD arithmetic and excels in its bit-handling capabilities. Efficient use of program
memory results from an instruction set consisting of 44 % one-byte, 41 % two-byte, and 15%
three-byte instructions. With a 12 MHz crystal, 58% of the instructions are executed in 1.0

24 MHz: 500 ns, 40 MHz : 300 ns).

Special Function Register PSW (Address D0H)

Reset Value : 00H

Bit

Function

Carry Flag
Used by arithmetic instruction.

Auxiliary Carry Flag
Used by instructions which execute BCD operations.

General Purpose Flag

RS1
RS0

Overflow Flag
Used by arithmetic instruction.

General Purpose Flag

Parity Flag
Set/cleared by hardware after each instruction to indicate an odd/even
number of "one" bits in the accumulator, i.e. even parity.

RS1

RS0

D0H

PSW

D7H

D6H

D5H

D4H

D3H

D2H

D1H

D0H

Bit No.

MSB

LSB

RS1

RS0

Function

Bank 0 selected, data address 00H-07H

Bank 1 selected, data address 08H-0FH

Bank 2 selected, data address 10H-17H

Bank 3 selected, data address 18H-1FH

Semiconductor Group

1997-04-01

C501

Memory Organization

The C501 CPU manipulates data and operands in the following four address spaces:

up to 64 Kbyte of internal/external program memory
up to 64 Kbyte of external data memory
256 bytes of internal data memory
a 128 byte special function register area

Figure 7 illustrates the memory address spaces of the C501.

Figure 7
C501 Memory Map

MCD03224

00 H

External

FFFF H

"Code Space"

"Data Space"

"Internal Data Space"

0000

RAM

Internal

RAM

FFH

Function

Special

Direct

Address

80 H

Address

Indirect

(EA = 0)

(EA = 1)

Internal

External

FFFF

External

0000

2000 H

1FFF H

C501

Semiconductor Group

1997-04-01

Special Function Registers

The registers, except the program counter and the four general purpose register banks, reside in
the special function register area.

The 27 special function registers (SFRs) include pointers and registers that provide an interface
between the CPU and the other on-chip peripherals. All SFRs with addresses where address bits
0-2 are 0 (e.g. 80H, 88H, 90H, 98H, ..., F8H, FFH) are bitaddressable.
The SFRs of the C501 are listed in table 2 and table 3. In table 2 they are organized in groups
which refer to the functional blocks of the C501. Table 3 illustrates the contents of the SFRs in
numeric order of their addresses.

Semiconductor Group

1997-04-01

C501

Table 2
Special Function Registers - Functional Blocks

Block

Symbol

Name

Address

Contents after
Reset

CPU

ACC
B
DPH
DPL
PSW
SP

Accumulator
B-Register
Data Pointer, High Byte
Data Pointer, Low Byte
Program Status Word Register
Stack Pointer

E0H

F0H

83H
82H
D0H

81H

00H
00H
00H
00H
00H
07H

Interrupt
System

IE
IP

Interrupt Enable Register
Interrupt Priority Register

A8H

B8H

0X000000B

XX000000B

Ports

P0
P1
P2
P3

Port 0
Port 1
Port 2
Port 3

80H

90H

A0H

B0H

FFH
FFH
FFH
FFH

Serial
Channel

PCON

SBUF
SCON

Power Control Register
Serial Channel Buffer Register
Serial Channel Control Register

87H
99H
98H

0XXX0000B

XXH

00H

Timer 0 /
Timer 1

TCON
TH0
TH1
TL0
TL1
TMOD

Timer 0/1 Control Register
Timer 0, High Byte
Timer 1, High Byte
Timer 0, Low Byte
Timer 1, Low Byte
Timer Mode Register

88H

8CH
8DH
8AH
8BH
89H

00H
00H
00H
00H
00H
00H

Timer 2

T2CON
T2MOD
RC2H
RC2L
TH2
TL2

Timer 2 Control Register
Timer 2 Mode Register
Timer 2 Reload/Capture Register, High Byte
Timer 2 Reload/Capture Register, Low Byt
Timer 2 High Byte
Timer 2 Low Byte

C8H

C9H
CBH
CAH
CDH
CCH

00H
XXXXXXX0B

00H
00H
00H
00H

Pow. Sav.
Modes

PCON

Power Control Register

87H

0XXX0000B

1) Bit-addressable special function registers
2) This special function register is listed repeatedly since some bits of it also belong to other functional blocks.
3) "X" means that the value is undefined and the location is reserved

C501

Semiconductor Group

1997-04-01

Table 3
Contents of the SFRs, SFRs in numeric order of their addresses

Addr Register Content

after
Reset

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

80H

FFH

81H SP

07H

82H DPL

00H

83H DPH

00H

87H PCON

0XXX-
0000B

SMOD

GF1

GF0

PDE

IDLE

88H

TCON

00H

TF1

TR1

TF0

TR0

IE1

IT1

IE0

IT0

89H TMOD

00H

GATE

C/T

GATE

C/T

8AH TL0

00H

8BH TL1

00H

8CH TH0

00H

8DH TH1

00H

90H

FFH

98H

SCON

00H

SM0

SM1

SM2

REN

TB8

RB8

99H SBUF

XXH

A0H

FFH

A8H

0X00-
0000B

ET2

ET1

EX1

ET0

EX0

B0H

FFH

INT1

INT0

TxD

RxD

B8H

XX00.
0000B

PT2

PT1

PX1

PT0

PX0

C8H

T2CON

00H

TF2

EXF2

RCLK

TCLK

EXEN2 TR2

C/T2

CP/RL2

C9H T2MOD

XXXX-
XXX0B

DCEN

CAH RC2L

00H

CBH RC2H

00H

CCH TL2

00H

CDH TH2

00H

D0H

PSW

00H

RS1

RS0

E0H

ACC

00H

F0H

00H

1) X means that the value is undefined and the location is reserved
2) Bit-addressable special function registers

Semiconductor Group

1997-04-01

C501

Timer / Counter 0 and 1

Timer/counter 0 and 1 can be used in four operating modes as listed in table 4.

In the "timer" function (C/T = `0') the register is incremented every machine cycle. Therefore the
count rate is

OSC

/12.

In the "counter" function the register is incremented in response to a 1-to-0 transition at its
corresponding external input pin (P3.4/T0, P3.5/T1). Since it takes two machine cycles to detect a
falling edge the max. count rate is

OSC

/24. External inputs INTO and INT1 (P3.2, P3.3) can be

programmed to function as a gate to facilitate pulse width measurements. Figure 8 illustrates the
input clock logic.

Figure 8
Timer/Counter 0 and 1 Input Clock Logic

Table 4
Timer/Counter 0 and 1 Operating Modes

Mode

Description

TMOD

Input Clock

Gate

C/T

internal

external (max)

8-bit timer/counter with a
divide-by-32 prescaler

OSC

16-bit timer/counter

OSC

8-bit timer/counter with
8-bit autoreload

OSC

Timer/counter 0 used as one
8-bit timer/counter and one
8-bit timer
Timer 1 stops

OSC

/12

MCS01768

OSC

C/T

TMOD

Control

Timer 0/1
Input Clock

TCON

TR 0/1

Gate

TMOD

P3.4/T0
P3.5/T1
max

P3.2/INT0
P3.3/INT1

OSC

/24

C501

Semiconductor Group

1997-04-01

Timer 2

Timer 2 is a 16-bit timer/counter with an up/down count feature. It can operate either as timer or as
an event counter which is selected by bit C/T2 (T2CON.1). It has three operating modes as shown
in table 5.

Note:

falling edge

Table 5
Timer/Counter 2 Operating Modes

Mode

T2CON

T2MOD

DCEN

T2CON

EXEN

P1.1/

T2EX

Remarks

Input Clock

CLK

CP/

RL2

TR2

internal

external

(P1.0/T2)

16-bit
Auto-
reload

0
0

1
1

X
X

0
1

reload upon
overflow
reload trigger
(falling edge)
Down counting
Up counting

OSC

/12

max

OSC

/24

16-bit
Cap-
ture

16 bit Timer/
Counter (only
up-counting)
capture TH2,
TL2

RC2H,

RC2L

OSC

/12

max

OSC

/24

Baud
Rate
Gene-
rator

no overflow
interrupt
request (TF2)
extra external
interrupt
("Timer 2")

OSC

max

OSC

/24

off

Timer 2 stops

Semiconductor Group

1997-04-01

C501

Serial Interface (USART)

The serial port is full duplex and can operate in four modes (one synchronous mode, three
asynchronous modes) as illustrated in table 6. The possible baudrates can be calculated using the
formulas given in table 7.

Table 6
USART Operating Modes

Mode

SCON

Baudrate

Description

SM0

SM1

OSC

/12

Serial data enters and exits through R

D outputs the shift clock. 8-bit are

transmitted/received (LSB first)

Timer 1/2 overflow rate

8-bit UART
10 bits are transmitted (through T

D) or

received (R

OSC

/32 or

OSC

/64

9-bit UART
11 bits are transmitted (T

D) or

received (R

Timer 1/2 overflow rate

9-bit UART
Like mode 2 except the variable baud rate

Table 7
Formulas for Calculating Baudrates

Baud Rate

derived from

Interface Mode

Baudrate

Oscillator

0
2

OSC

/12

SMOD

OSC

) / 64

Timer 1 (16-bit timer)

(8-bit timer with

8-bit autoreload)

1,3
1,3

SMOD

timer 1 overflow rate) /32

SMOD

OSC

) / (32

(256-TH1))

Timer 2

1,3

OSC

/ (32

(65536-(RC2H, RC2L))

C501

Semiconductor Group

1997-04-01

Interrupt System

The C501 provides 6 interrupt sources with two priority levels. Figure 9 gives a general overview of
the interrupt sources and illustrates the request and control flags.

Figure 9
Interrupt Request Sources

Timer 2 Overflow

Timer 1 Overflow

MCS01783

TF0

ET0

P1.1/
T2EX

P3.2/
INT0

High Priority

Timer 0 Overflow

TCON.5

PT0

Low Priority

PT1

TCON.7

ET1

TF1

IE.1

IP.1

IP.3

T2CON.3

TF2

EXEN2

T2CON.7

PT2

EXF2

SCON.0

IE.5

IP.5

IP.4

IE.4

IE0

EX0

TCON.1

PX0

ET2

IE.3

IT0

IT1

PX1

TCON.3

EX1

IE1

IE.0

IP.0

INT1

P3.3/

IE.7

TCON.0

TCON.2

SCON.1

T2CON.6

TCON.0

IE.2

IP.2

USART

Semiconductor Group

1997-04-01

C501

A low-priority interrupt can itself be interrupted by a high-priority interrupt, but not by another low-
priority interrupt. A high-priority interrupt cannot be interrupted by any other interrupt source.

If two requests of different priority level are received simultaneously, the request of higher priority is
serviced. If requests of the same priority are received simultaneously, an internal polling sequence
determines which request is serviced. Thus within each priority level there is a second priority
structure determined by the polling sequence as shown in table 9.

Table 8
Interrupt Sources and their Corresponding Interrupt Vectors

Source (Request Flags)

Vector

Vector Address

IE0
TF0
IE1
TF1
RI + TI
TF2 + EXF2

External interrupt 0
Timer 0 interrupt
External interrupt 1
Timer 1 interrupt
Serial port interrupt
Timer 2 interrupt

0003H
000BH
0013H
001BH
0023H
002BH

Table 9
Interrupt Priority-Within-Level

Interrupt Source

Priority

External Interrupt 0,
Timer 0 Interrupt,
External Interrupt 1,
Timer 1 Interrupt,
Serial Channel,
Timer 2 Interrupt,

IE0
TF0
IE1
TF1
RI + TI
TF2 + EXF2

High

Low

C501

Semiconductor Group

1997-04-01

Power Saving Modes

Two power down modes are available, the Idle Mode and Power Down Mode.

The bits PDE and IDLE of the register PCON select the Power Down mode or the Idle mode,
respectively. If the Power Down mode and the Idle mode are set at the same time, the Power Down
mode takes precedence. Table 10 gives a general overview of the power saving modes.

In the Power Down mode of operation,

can be reduced to minimize power consumption. It must

be ensured, however, that

is not reduced before the Power Down mode is invoked, and that

is restored to its normal operating level, before the Power Down mode is terminated. The reset
signal that terminates the Power Down mode also restarts the oscillator. The reset should not be
activated before

is restored to its normal operating level and must be held active long enough

to allow the oscillator to restart and stabilize (similar to power-on reset).

Table 10
Power Saving Modes Overview

Mode

Entering
Instruction
Example

Leaving by

Remarks

Idle mode

ORL PCON, #01H

enabled interrupt
Hardware Reset

CPU is gated off
CPU status registers maintain
their data.
Peripherals are active

Power-Down
Mode

ORL PCON, #02H

Hardware Reset

Oscillator is stopped, contents
of on-chip RAM and SFR's are
maintained (leaving Power
Down Mode means redefinition
of SFR contents).

Semiconductor Group

1997-04-01

C501

OTP Operation

The C501-1E is programmed by usng a modified Quick-Pulse Programming

TM 1)

algorithm. It differs

from older methods in the value used for V

(programming supply voltage) and in the width and

number of the ALE/PROG pulses. The C501-1E contains two signature bytes that can be read and
used by a programming system to identify the device. The signature bytes identify the manufacturer
of the device.

Table 11 shows the logic levels for reading the signature byte, and for programming the program
memory, the encryption table, and the security bits. The circuit configuration and waveforms for
quick-pulse programming are shown in figures 10 to 12.

Notes :

1. "0" = valid low for that pin, "1" = valid high for that pin.
2. V

= 12.75 V

0.25V

3. V

= 5 V

10% during programming and verification.

4. ALE/PROG receives 25 programming pulses while V

is held at 12.75 V. Each programming pulse is low for

100

s (

s) and high for a minimum of 10

Quick-Pulse Programming

is a trademark phrase of Intel Corporation

Table 11
OTP Programming Modes

Mode

RESET

PSEN

ALE/

PROG

EA/V

P2.7

P2.6

P3.7

P3.6

Read signature

Program code data

Verify code data

Progam encryption table

Program security bit 1

Program security bit 2

C501

Semiconductor Group

1997-04-01

Quick-Pulse Programming

The setup for microcontroller quick-pulse programming is shown in figure 10. Note that the C501-
1E is running with a 4 to 6 MHz oscillator The reason the oscillator needs to be running is that the
device is executing internal address and program data transfers.

The address of the OTP memory location to be programmed is applied to port 1 and 2 as shown in
figure 10. The code byte to be programmed into that location is applied to port 0. RESET, PSEN
and pins of port 2 and 3 specified in table 11 are held at the "Program code data" levels. The ALE/
PROG signal is pulsed low 25 times as shown in figure 11.

For programming of the encryption table, the 25 pulse programming sequence must be repeated for
addresses 0 through 1FH, using the "Program encrytion table" levels. After the encryption table is
programmed, verification cycles will produce only encrypted data.

For programming of the security bits, the 25 pulse programming sequence must be repeat using the
"Program security bit" levels. After one security bit is programmed, further programming of the code
memory and encryption table is disabled. However, the other security bit can still be programmed.

Note that the EA/V

pin must not be allowed to go above the maximum specified V

level. for any

amount of time. Even a narrow glitch above that voltage can cause permanent damage to the
device. The V

source should be well regulated and free of glitches and overshoots.

Program Verification

If security bit 2 has not been programmed, the on-chip OTP program memory can be read out for
program verification. The address of the OTP program memory locations to be read is applied to
ports 1 and 2 as shown in figure 12. The other pins are held at the "Verify code data" levels
indicated in table 11. The contents of the address location will be emitted on port 0. External pullups
are required on port 0 for this operation.

If the encryption table has been programmed, the data presented at port 0 will be the exclusive NOR
of the program byte with one of the encryption bytes. The user will have to know the encryption
table contents in order to correctly decode the verification data. The encryption table itself cannot be
read out.

Reading the SIgnature Bytes

The signature bytes are read by the same procedure as a normal verification of loctions 30H and
31H, except that P3.6 and P3.7 need to be pulled to a logic low. The values are :

30H = E0H indicates manufacturer
31H = 71H indicates C501-1E

Semiconductor Group

1997-04-01

C501

Absolute Maximum Ratings

Ambient temperature under bias (

) ......................................................... 40 to 85

Storage temperature (

stg

) .......................................................................... 65

C to 150

Voltage on

pins with respect to ground (

) ....................................... 0.5 V to 6.5 V

Voltage on any pin with respect to ground (

) ......................................... 0.5 V to

+0.5 V

Input current on any pin during overload condition..................................... 10 mA to 10 mA
Absolute sum of all input currents during overload condition ..................... I 100 mA I
Power dissipation........................................................................................ TBD

Note: Stresses above those listed under "Absolute Maximum Ratings" may cause permanent

damage of the device. This is a stress rating only and functional operation of the device at
these or any other conditions above those indicated in the operational sections of this
specification is not implied. Exposure to absolute maximum rating conditions for longer
periods may affect device reliability. During overload conditions (

) the

Voltage on

pins with respect to ground (

) must not exceed the values defined by the

absolute maximum ratings.

C501

Semiconductor Group

1997-04-01

DC Characteristics for C501-L / C501-1R

= 5 V + 10 %, 15 %;

= 0 V;

= 0 °C to 70 °C

for the SAB-C501

= 40 °C to 85 °C

for the SAF-C501

Notes see page 32.

Parameter

Symbol

Limit Values

Unit Test Condition

min.

max.

Input low voltage (except EA,
RESET)

0.5

0.2

0.1 V

Input low voltage (EA)

IL 1

0.5

0.2

0.3 V

Input low voltage (RESET)

IL 2

0.5

0.2

+ 0.1 V

Input high voltage (except
XTAL1, EA, RESET)

0.2

+ 0.9

+ 0.5

Input high voltage to XTAL1

IH 1

0.7

+ 0.5

Input high voltage to EA,
RESET

IH 2

0.6

+ 0.5

Output low voltage
(ports 1, 2, 3)

0.45

= 1.6 mA

Output low voltage
(port 0, ALE, PSEN)

OL 1

0.45

= 3.2 mA

Output high voltage
(ports 1, 2, 3)

2.4
0.9

= 80

= 10

Output high voltage
(port 0 in external bus mode,
ALE, PSEN)

OH 1

2.4
0.9

= 800

= 80

Logic 0 input current
(ports 1, 2, 3)

= 0.45 V

Logical 1-to-0 transition
current (ports 1, 2, 3)

650

= 2 V

Input leakage current
(port 0, EA)

0.45 <

Pin capacitance

= 1 MHz,

= 25 °C

Power supply current:

Active mode, 12 MHz

Idle mode, 12 MHz

Active mode, 24 MHz

Idle mode, 24 MHz

Active mode, 40 MHz

Idle mode, 40 MHz

Power Down Mode

21
4.8
36.2
8.2
56.5
12.7
50

mA
mA
mA
mA
mA
mA

= 5 V,

= 2 ... 5.5 V

Semiconductor Group

1997-04-01

C501

DC Characteristics for C501-1E

= 5 V + 10 %, 15 %;

= 0 V;

= 0 °C to 70 °C

for the SAB-C501

= 40 °C to 85 °C

for the SAF-C501

Notes see next page.

Parameter

Symbol

Limit Values

Unit Test Condition

min.

max.

Input low voltage (except
EA/V

, RESET)

0.5

0.2

0.1 V

Input low voltage (EA/V

)

IL 1

0.5

0.1

0.1 V

Input low voltage (RESET)

IL 2

0.5

0.2

+ 0.1 V

Input high voltage (except
XTAL1, EA/V

, RESET)

0.2

+ 0.9

+ 0.5

Input high voltage to XTAL1

IH 1

0.7

+ 0.5

Input high voltage to EA/V

RESET

IH 2

0.6

+ 0.5

Output low voltage
(ports 1, 2, 3)

0.45

= 1.6 mA

Output low voltage
(port 0, ALE/PROG, PSEN)

OL 1

0.45

= 3.2 mA

Output high voltage
(ports 1, 2, 3)

2.4
0.9

= 80

= 10

Output high voltage
(port 0 in external bus mode,
ALE/PROG, PSEN)

OH 1

2.4
0.9

= 800

= 80

Logic 0 input current
(ports 1, 2, 3)

= 0.45 V

Logical 1-to-0 transition
current (ports 1, 2, 3)

650

= 2 V

Input leakage current
(port 0, EA/V

)

0.45 <

Pin capacitance

= 1 MHz,

= 25 °C

Power supply current:

Active mode, 12 MHz

Idle mode, 12 MHz

Active mode, 24 MHz

Idle mode, 24 MHz

Power Down Mode

21
18
36.2
20
50

mA
mA
mA
mA

= 5 V,

= 2 ... 5.5 V

C501

Semiconductor Group

1997-04-01

Notes:

Capacitive loading on ports 0 and 2 may cause spurious noise pulses to be superimposed on the

of ALE

and port 3. The noise is due to external bus capacitance discharging into the port 0 and port 2 pins when these
pins make 1-to-0 transitions during bus operation. In the worst case (capacitive loading > 100 pF), the noise
pulse on ALE line may exceed 0.8 V. In such cases it may be desirable to qualify ALE with a schmitt-trigger,
or use an address latch with a schmitt-trigger strobe input.

Capacitive loading on ports 0 and 2 may cause the

on ALE and PSEN to momentarily fall bellow the

0.9

specification when the address lines are stabilizing.

(Power Down Mode) is measured under following conditions:

EA = Port0 =

; RESET =

; XTAL2 = N.C.; XTAL1 =

; all other pins are disconnected.

(active mode) is measured with:

XTAL1 driven with

CLCH

CHCL

= 5 ns,

+ 0.5 V,

0.5 V; XTAL2 = N.C.;

EA = Port0 = RESET=

; all other pins are disconnected.

would be slightly higher if a crystal oscillator is

used (appr. 1 mA).

(Idle mode) is measured with all output pins disconnected and with all peripherals disabled;

XTAL1 driven with

CLCH

CHCL

= 5 ns,

+ 0.5 V,

0.5 V; XTAL2 = N.C.;

RESET = EA =

; Port0

= V

; all other pins are disconnected;

CC max

at other frequencies is given by:

active mode:

= 1.27 x

OSC

+ 5.73

idle mode:

= 0.28 x

OSC

+ 1.45 (C501-L and C501-1R only)

where

OSC

is the oscillator frequency in MHz.

values are given in mA and measured at

= 5 V.

Semiconductor Group

1997-04-01

C501

AC Characteristics for C501-L / C501-1R / C501-1E

= 5 V + 10 %, 15 %;

= 0 V

= 0 °C to 70 °C

for the SAB-C501

= 40 °C to 85 °C for the SAF-C501

(

for port 0, ALE and PSEN outputs = 100 pF;

for all other outputs = 80 pF)

Program Memory Characteristics

*) Interfacing the C501 to devices with float times up to 75 ns is permissible. This limited bus contention will not

cause any damage to port 0 Drivers.

Parameter

Symbol

Limit Values

Unit

12 MHz

Clock

Variable Clock

CLCL

= 3.5 MHz to 12 MHz

min.

max.

min.

max.

ALE pulse width

LHLL

127

CLCL

Address setup to ALE

AVLL

CLCL

Address hold after ALE

LLAX

CLCL

ALE low to valid instr in

LLIV

233

CLCL

100

ALE to PSEN

LLPL

CLCL

PSEN pulse width

PLPH

215

CLCL

PSEN to valid instr in

PLIV

150

CLCL

100

Input instruction hold after PSEN

PXIX

Input instruction float after PSEN

PXIZ

CLCL

Address valid after PSEN

PXAV

CLCL

Address to valid instr in

AVIV

302

CLCL

115

Address float to PSEN

AZPL

C501

Semiconductor Group

1997-04-01

AC Characteristics for C501-L / C501-1R / C501-1E (cont'd)

External Data Memory Characteristics

External Clock Drive Characteristics

Parameter

Symbol

Limit Values

Unit

12 MHz

Clock

Variable Clock

CLCL

= 3.5 MHz to 12 MHz

min.

max.

min.

max.

RD pulse width

RLRH

400

CLCL

100

WR pulse width

WLWH

400

CLCL

100

Address hold after ALE

LLAX2

CLCL

RD to valid data in

RLDV

252

CLCL

165

Data hold after RD

RHDX

Data float after RD

RHDZ

CLCL

ALE to valid data in

LLDV

517

CLCL

150

Address to valid data in

AVDV

585

CLCL

165

ALE to WR or RD

LLWL

200

300

CLCL

+ 50

Address valid to WR or RD

AVWL

203

CLCL

130

WR or RD high to ALE high

WHLH

123

CLCL

+ 40

Data valid to WR transition

QVWX

CLCL

Data setup before WR

QVWH

433

CLCL

150

Data hold after WR

WHQX

CLCL

Address float after RD

RLAZ

Parameter

Symbol

Limit Values

Unit

Variable Clock

Freq. = 3.5 MHz to 12 MHz

min.

max.

Oscillator period

CLCL

83.3

285.7

High time

CHCX

CLCL

CLCX

Low time

CLCX

CLCL

CHCX

Rise time

CLCH

Fall time

CHCL

Semiconductor Group

1997-04-01

C501

AC Characteristics for C501-L24 / C501-1R24 / C501-1E24

= 5 V + 10 %, 15 %;

= 0 V

= 0 °C to 70 °C

for the SAB-C501

= 40 °C to 85 °C for the SAF-C501

(

for port 0, ALE and PSEN outputs = 100 pF;

for all other outputs = 80 pF)

Program Memory Characteristics

*) Interfacing the C501 to devices with float times up to 37 ns is permissible. This limited bus contention will not

cause any damage to port 0 Drivers.

Parameter

Symbol

Limit Values

Unit

24 MHz

Clock

Variable Clock

CLCL

= 3.5 MHz to 24 MHz

min.

max.

min.

max.

ALE pulse width

LHLL

CLCL

Address setup to ALE

AVLL

CLCL

Address hold after ALE

LLAX

CLCL

ALE low to valid instr in

LLIV

CLCL

ALE to PSEN

LLPL

CLCL

PSEN pulse width

PLPH

CLCL

PSEN to valid instr in

PLIV

CLCL

Input instruction hold after PSEN

PXIX

Input instruction float after PSEN

PXIZ

CLCL

Address valid after PSEN

PXAV

CLCL

Address to valid instr in

AVIV

148

CLCL

Address float to PSEN

AZPL

C501

Semiconductor Group

1997-04-01

AC Characteristics for C501-L24 / C501-1R24 / C501-1E24 (cont'd)

External Data Memory Characteristics

External Clock Drive Characteristics

Parameter

Symbol

Limit Values

Unit

24 MHz

Clock

Variable Clock

CLCL

= 3.5 MHz to 24 MHz

min.

max.

min.

max.

RD pulse width

RLRH

180

CLCL

WR pulse width

WLWH

180

CLCL

Address hold after ALE

LLAX2

CLCL

RD to valid data in

RLDV

118

CLCL

Data hold after RD

RHDX

Data float after RD

RHDZ

CLCL

ALE to valid data in

LLDV

200

CLCL

133

Address to valid data in

AVDV

220

CLCL

155

ALE to WR or RD

LLWL

175

CLCL

+ 50

Address valid to WR or RD

AVWL

CLCL

WR or RD high to ALE high

WHLH

CLCL

+ 25

Data valid to WR transition

QVWX

CLCL

Data setup before WR

QVWH

170

CLCL

122

Data hold after WR

WHQX

CLCL

Address float after RD

RLAZ

Parameter

Symbol

Limit Values

Unit

Variable Clock

Freq. = 3.5 MHz to 24 MHz

min.

max.

Oscillator period

CLCL

41.7

285.7

High time

CHCX

CLCL

CLCX

Low time

CLCX

CLCL

CHCX

Rise time

CLCH

Fall time

CHCL

Semiconductor Group

1997-04-01

C501

AC Characteristics for C501-L40 / C501-1R40

= 5 V + 10 %, 15 %;

= 0 V

= 0 °C to 70 °C

for the SAB-C501

= 40 °C to 85 °C for the SAF-C501

(

for port 0, ALE and PSEN outputs = 100 pF;

for all other outputs = 80 pF)

Program Memory Characteristics

*) Interfacing the C501 to devices with float times up to 25ns is permissible. This limited bus contention will not

cause any damage to port 0 Drivers.

Parameter

Symbol

Limit Values

Unit

40 MHz

Clock

Variable Clock

CLCL

= 3.5 MHz to 40 MHz

min.

max.

min.

max.

ALE pulse width

LHLL

CLCL

Address setup to ALE

AVLL

CLCL

Address hold after ALE

LLAX

CLCL

ALE low to valid instr in

LLIV

CLCL

ALE to PSEN

LLPL

CLCL

PSEN pulse width

PLPH

CLCL

PSEN to valid instr in

PLIV

CLCL

Input instruction hold after PSEN

PXIX

Input instruction float after PSEN

PXIZ

CLCL

Address valid after PSEN

PXAV

CLCL

Address to valid instr in

AVIV

CLCL

Address float to PSEN

AZPL

C501

Semiconductor Group

1997-04-01

AC Characteristics for C501-L40 / C501-1R40 (cont'd)

External Data Memory Characteristics

External Clock Drive Characteristics

Parameter

Symbol

Limit Values

Unit

40 MHz

Clock

Variable Clock

CLCL

= 3.5 MHz to 40 MHz

min.

max.

min.

max.

RD pulse width

RLRH

120

CLCL

WR pulse width

WLWH

120

CLCL

Address hold after ALE

LLAX2

CLCL

RD to valid data in

RLDV

CLCL

Data hold after RD

RHDX

Data float after RD

RHDZ

CLCL

ALE to valid data in

LLDV

150

CLCL

Address to valid data in

AVDV

150

CLCL

ALE to WR or RD

LLWL

CLCL

+ 15

Address valid to WR or RD

AVWL

CLCL

WR or RD high to ALE high

WHLH

CLCL

+ 15

Data valid to WR transition

QVWX

CLCL

Data setup before WR

QVWH

125

CLCL

Data hold after WR

WHQX

CLCL

Address float after RD

RLAZ

Parameter

Symbol

Limit Values

Unit

Variable Clock

Freq. = 3.5 MHz to 40 MHz

min.

max.

Oscillator period

CLCL

285.7

High time

CHCX

CLCL

CLCX

Low time

CLCX

CLCL

CHCX

Rise time

CLCH

Fall time

CHCL

C501

Semiconductor Group

1997-04-01

ROM Verification Characteristics for C501-1R

ROM Verification Mode 1

Figure 17
ROM Verification Mode 1

Parameter

Symbol

Limit Values

Unit

min.

max.

Address to valid data

AVQV

CLCL

ENABLE to valid data

ELQV

CLCL

Data float after ENABLE

EHQZ

CLCL

Oscillator frequency

CLCL

MHz

MCT00049

AVQV

EHQZ

ELQV

Address

Data OUT

P1.0 - P1.7
P2.0 - P2.4

Port 0

P2.7

ENABLE

Inputs: P2.5 - P2.6, PSEN =

ALE, EA =

RESET =

P0.0 - P0.7 = D0 - D7

Data:

P2.0 - P2.4 = A8 - A12

Address: P1.0 - P1.7 = A0 - A7

Semiconductor Group

1997-04-01

C501

OTP Programming and Verification Characteristics

= 5 V

10%,

= 0 V

, T

= 21 °C to + 27 °C

Parameter

Symbol

Limit Values

Unit

min.

max.

Programming supply voltage

12.5

13.0

Programming supply current

Oscillator frequency

1 /

CLCL

MHz

Address setup to ALE/PROG low

AVGL

CLCL

Address hold after ALE/PROG

GHAX

CLCL

Data setup to ALE/PROG low

DVGL

CLCL

Data hold after ALE/PROG

GHDX

CLCL

P2.7 (ENABLE) high to V

EHSH

CLCL

setup to ALE/PROG low

SHGL

hold after ALE/PROG low

GHSL

ALE/PROG width

GLGH

110

Address to data valid

AVQV

CLCL

ENABLE low to data valid

ELQV

CLCL

Data float after ENABLE

EHQZ

CLCL

ALE/PROG high to ALE/PROG low

GHGL

Semiconductor Group

1997-04-01

C501

Figure 19
AC Testing: Input, Output Waveforms

Figure 20
AC Testing: Float Waveforms

Figure 21
Recommended Oscillator Circuits

0.45 V

0.2

-0.1

+0.9

0.2

Test Points

MCT00039

-0.5 V

AC Inputs during testing are driven at

0.5 V for a logic `1' and 0.45 V for a logic `0'. Timing

measurements are made at

IHmin

for a logic `1' and

ILmax

for a logic `0'.

MCT00038

Load

-0.1 V

+0.1 V

Load

Timing Reference

Points

-0.1 V

+0.1 V

For timing purposes a port pin is no longer floating when a 100 mV change from load voltage
occurs and begins to float when a 100 mV change from the loaded

level occurs.

20 mA.

MCS02452

XTAL1

XTAL2

XTAL1

Crystal Oscillator Mode

Driving from External Source

External Oscillator
Signal

N.C.

20 pF

3.5 - 40 MHz

C =

(incl. stray capacitance)

P-LCC-44/Pin 20
P-DIP-40/Pin 18
M-QFP-44/Pin 14

M-QFP-44/Pin 15

P-DIP-40/Pin 19

P-LCC-44/Pin 21

M-QFP-44/Pin 14

P-DIP-40/Pin 18

P-LCC-44/Pin 20

P-LCC-44/Pin 21
P-DIP-40/Pin 19
M-QFP-44/Pin 15

Note: During programming and verification of the C501-1E OTP memory

a clock signal of 4-6 MHz must be applied to the device.

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ÐÐ»ÐµÐºÑ‚Ñ€Ð¾Ð½Ð½Ñ‹Ð¹ ÐºÐ¾Ð¼Ð¿Ð¾Ð½ÐµÐ½Ñ‚: SAB-C501G-1E24N