Service manual

SERVICE MANUAL

Microcontroller S3P8849XZZ/CH12T1007

S3C8835/C8837/P8837/P8849

The S3C8835 microcontroller has 16K bytes of on-chip program memory and the S3C8837 has

24K bytes. Both chips have a 272-byte general-purpose internal register file. The interrupt

structure has seven interrupt sources with six interrupt vectors. The CPU recognizes six interrupt

priority levels.

Using a modular design approach, the following peripherals were integrated with the SAM87 core

to make the S3C8835/C8837/P8837/P8849 suitable for use in color television and other types of

screen display applications:

- Four programmable I/O ports (26 pins total: 16 general-purpose I/O pins; 8 n-channel, open-drain

output pins)

- 2 channel A/D converter (4-bit resolution)

- 14-bit PWM output (one channel: push-pull type)

- Basic timer (BT) with watchdog timer function

- One 8-bit timer/counter (T0) with interval timer

- One 8-bit general-purpose timer/counter (TA) with prescalers

- On-screen display (OSD) with a wide range of programmable features including halftone control

signal output

1. Features

CPU

· SAM87 CPU core

Memory

· 16-K byte (S3C8835) or 24K- byte (S3C8837) internal program memory

· 272-byte general-purpose register area

Instruction Set

· 78 instructions

· IDLE and STOP instructions added for powerdown modes

Instruction Execution Time

· 750 ns (minimum) with an 8-MHz CPU clock

Interrupts

· 7 interrupt sources with 6 vectors

· 6 interrupt levels

· Fast interrupt processing for select levels

General I/O

· Four I/O ports (26 pins total)

· Six open-drain pins for up to 6-volt loads

· Two open-drain pins for up to 5-volt loads

8-Bit Basic Timer

· Three selectable internal clock frequencies

· Watchdog or oscillation stabilization function

Timer/Counters

· One 8-bit timer/counter (T0) with three internal clocks and interval timer mode.