Seiko Instruments Inc.
1
The S-7292AF is a CMOS 4-bit microcomputer for telephone sets,
which integrates ROM, RAM, timers, a serial I/O, I/O ports and a dialer
circuit on one chip. It features low voltage operation and low current
consumption. At power failure, it is powered solely by telephone line
input. It is usable for wireless telephone set and multi-function telphone
set.
Applications
Standard telephone set, wireless telephone set, answering machine
Personal facsimile
1-chip MICROCOMPUTER FOR TELEPHONE SET
S-7292AF
Features
Characteristics
Power supply voltage:
1.7 to 5.5 V (PULSE mode, a crystal used)
2.0 to 5.5 V (DTMF mode)
Current consumption: Running:
0.20 mA typ. in PULSE mode, 2.4V operation
0.35 mA typ. in DTMF mode, 2.4V operation
Standby:
2.5
A max., 2.4V operation
Instruction execution time : 17.9
s (operating frequency : 224kHz)
Hardware functions
ROM : 3K
16 bits
RAM : 768
4 bits
I/O line : 33 [10 inputs, 12 outputs, 11 I/O (including key interface)]
Serial I/O : 1 ch (8-bit clock syncronization)
Timer :
Timer 1 (8-bit general-purpose timer with reload function)
Timer 2 (8-bit dial pulse timer)
Interval timer (selectable from 150 / 300Hz)
Watchdog timer
4 pins for telephone use : HS (HS), BEEP, KT, TONE-OUT
Interrupt function: Internal (three), external (four)
Oscillation circuit : Crystal or ceramic oscillator (3.579545MHz)
Software
Instruction: 35 basic instruction sets (166 when addressing modes are included)
16-level subroutine nesting
Package
44-pin QFP
OTP version
S-72P92AF (its electrical characteristics differ from those of S-7292AF)
1-chip MICROCOMPUTER FOR TELEPHONE SET
S-7292AF
Seiko Instruments Inc.
3
Terminal Functions
Block Diagram
The S-7292AF blocks connect with a 4-bit data bus(DB), 4-bit address bus(AB), 4-bit RAM address
bus(RA) and 12-bit operation bus(OB).
Pin name
I/O
Functions
V
SS
COMMON potential terminal
V
DD
Positive power supply
TEST
Input
Test, usually connected to V
DD
(built-in pull-up resistor)
AC
Input
Reset (built-in pull-up resistor, schmitt trigger input)
X
IN
X
OUT
Input
Output
Crystal/ceramic oscillator connection terminal for system clock oscillation or DTMF signal
generation
HS
Input
Hook switch input
BEEP
Output
Buzzer output
TONE-OUT
Output
DTMF signal output (Pch open-drain output)
KT
Output
Key-in-tone output
R
0
to R
5
Input
Row signal input (built-in pull-up resistor)
C
1
to C
4
Output
Column signal output (see the description of PO
4
to PO
7
for C
5
to C
8
)
PI
0
to PI
3
Input
4-bit input port (Port 0). PI
0
is shared with the following function:
PI
0
/INTA : external interrupt (schmitt trigger input)
PO
0
to PO
3
Output
4-bit output port (Port 1). PO
3
is shared with the following function:
PO
3
/DP(PO
3
/DP) : dial pulse output
PO
4
to PO
7
Output
4-bit output port (Port 5). PO
4
to PO
7
are shared with Column signal outputs as follows:
PO
4
/C
5
, PO
5
/C
6
, PO
6
/C
7
, PO
7
/C
8
PIO
0
to PIO
3
I/O
4-bit input/output port (Port 3), selectable in bit unit.
PIO
4
to PIO
6
I/O
3-bit input/output port (Port 4), selectable in bit unit. PIO
4
to PIO
6
are shared with Column
signal outputs as follows (PIO
4
and PIO
6
are schmitt trigger input):
PIO
4
/SCK: serial clock input/output
PIO
5
/SO : serial data output
PIO
6
/SI :
serial data input
PIO
8
to PIO
11
I/O
4-bit input/output port (Port 2), selectable in bit unit.
NC
V
PP
terminal for S-72P92AF
INTA
ITM (150/300 Hz)
SYSCLK
DP(DP)
INTA
HS
TONE-OUT
ROM
Flag
A
CCB
Page
register
RAM
Stack
Stack pointer
ACCA
AL
U
V
DD
V
SS
DB
OB
AB
Program
counter
RA
AC
DTMF
generator
System clock
generation circuit
X
OUT
X
IN
Port 0
buffer
Instruction
decoder
Interrupt
vector
table
Interrupt
control
Timer 1
PIO
4
/SCK
PIO
5
/SO
PIO
6
/SI
Port 4
buffer
TEST
Key input
PI
0
to PI
3
DP
generator
Port 1
buffer
PO
0
to PO
3
Port 2
buffer
PIO
8
to PIO
11
Port 3
buffer
PIO
0
to PIO
3
Serial
interface
Buzzer
driving
circuit
KT
BEEP
Key
interface
C
1
to C
8
R
0
to R
5
Port 5
buffer
PO
4
to PO
7
Watchdog
timer
Hook switch
interface
HS
74 Hz 2071 Hz
Timer 2
74 Hz 2071 Hz DP
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