Table of Contents
1. OVERVIEW ...........................................1
Description ......................................................... 1
Features .............................................................1
Development Tools ............................................2
Ordering Information ..........................................2
2. BLOCK DIAGRAM ................................3
3. PIN ASSIGNMENT ...............................4
4. PACKAGE DIAGRAM
.............................. 6
5. PIN FUNCTION .....................................8
6. PORT STRUCTURES .........................11
7. ELECTRICAL CHARACTERISTICS ... 14
Absolute Maximum Ratings ............................. 14
Recommended Operating Conditions.............. 14
A/D Converter Characteristics ......................... 14
DC Electrical Characteristics for Standard Pins(5V)
..........................................................................15
DC Electrical Characteristics for High-Voltage Pins
..........................................................................16
AC Characteristics ...........................................17
AC Characteristics ...........................................18
Typical Characteristics .....................................19
8. MEMORY ORGANIZATION................ 21
Registers .......................................................... 21
Program Memory ............................................. 24
Data Memory ...................................................27
Addressing Mode .............................................31
9. I/O PORTS ..........................................35
10. BASIC INTERVAL TIMER .................39
11. WATCHDOG TIMER......................... 41
12. TIMER/EVENT COUNTER ............... 44
8-bit Timer / Counter Mode .............................. 46
16-bit Timer / Counter Mode ............................50
8-bit Compare Output (16-bit) ..........................51
8-bit Capture Mode ..........................................51
16-bit Capture Mode ........................................54
PWM Mode ......................................................55
13. ANALOG DIGITAL CONVERTER ....58
14. SERIAL PERIPHERAL INTERFACE 61
Transmission/Receiving Timing ...................... 63
The method of Serial I/O ................................. 64
The Method to Test Correct Transmission ...... 64
15. BUZZER FUNCTION ........................65
16. INTERRUPTS ...................................67
Interrupt Sequence .......................................... 69
Multi Interrupt .................................................. 71
External Interrupt ............................................. 72
17. Power Saving Mode.......................... 74
Operating Mode .............................................. 75
Stop Mode ....................................................... 76
Wake-up Timer Mode ...................................... 77
Internal RC-Oscillated Watchdog Timer Mode 78
Minimizing Current Consumption .................... 79
18. OSCILLATOR CIRCUIT ....................81
19. RESET .............................................. 82
External Reset Input ........................................ 82
Watchdog Timer Reset ................................... 82
20. POWER FAIL PROCESSOR ............83
21. OTP PROGRAMMING...................... 85
DEVICE CONFIGURATION AREA ...................... 85
A. CONTROL REGISTER LIST ................. i
B. INSTRUCTION .................................... iii
Terminology List................................................ iii
Instruction Map ..................................................iv
Instruction Set .................................................... v
C.MASK ORDER SHEET ........................ xi
HYUNDAI MicroElectronics
GMS81C2012/GMS81C2020
MAR. 2000 Ver 1.00
5
GMS81C2012/GMS81C2020
CMOS Single-Chip 8-Bit Microcontroller
with A/D Converter & VFD Driver
1. OVERVIEW
1.1 Description
The GMS81C2012 and GMS81C2020 are advanced CMOS 8-bit microcontroller with 12K/20K bytes of ROM. These are a
powerful microcontroller which provides a highly flexible and cost effective solution to many VFD applications. These pro-
vide the following standard features: 12K/20K bytes of ROM, 448 bytes of RAM, 8-bit timer/counter, 8-bit A/D converter,
10-bit High Speed PWM Output, Programmable Buzzer Driving Port, 8-bit Basic Interval Timer, 7-bit Watch dog Timer,
Serial Peripheral Interface, on-chip oscillator and clock circuitry. They also come with high voltage I/O pins that can directly
drive a VFD (Vacuum Fluorescent Display). In addition, the GMS81C2012 and GMS81C2020 support power saving modes
to reduce power consumption.
1.2 Features
20K/12K bytes ROM(EPROM)
448 Bytes of On-Chip Data RAM
(Including STACK Area)
Minimum Instruction Execution time:
- 1uS at 4MHz (2cycle NOP Instruction)
One 8-bit Basic Interval Timer
One 7-bit Watch Dog Timer
Two 8-bit Timer/Counters
10-bit High Speed PWM Output
One 8-bit Serial Peripheral Interface
Two External Interrupt Ports
One Programmable 6-bit Buzzer Driving Port
60 I/O Lines
- 56 Programmable I/O pins
(Included 30 high-voltage pins Max. 40V)
- Three Input Only pins: 1 high-voltage pin
- One Output Only pin
Eight Interrupt Sources
- Two External Sources (INT0, INT1)
- Two Timer/Counter Sources (Timer0, Timer1)
- Four Functional Sources (SPI,ADC,WDT,BIT)
12-Channel 8-bit On-Chip Analog to Digital
Converter
Oscillator:
- Crystal
- Ceramic Resonator
- External R Oscillator
Low Power Dissipation Modes
- STOP mode
- Wake-up Timer Mode
- Standby Mode
- Watch Mode
- Sub-active Mode
Operating Voltage: 2.7V ~ 5.5V (at 4.5MHz)
Operating Frequency: 1MHz ~ 4.5MHz
Sub-clock: 32.768KHz Crystal Oscillator
Enhanced EMS Improvement
Power Fail Processor
(Noise Immunity Circuit)
Device name
ROM Size
RAM Size
OTP
Package
GMS81C2012
12K bytes
448 bytes
-
64SDIP, 64MQFP,
64LQFP
GMS81C2020
20K bytes
GMS87C2020
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