Circuit Description - Samsung sf150t Service Manual

5. Circuit Description

5-1 General
The main circuit board controls the machine, and consists of Super Fax Chip (KS16118), External memory,
CODEC circuit with modem-TX and RX signal path and some parts of the Line Interface Unit, Digital TAD
circuit with DSP amd DRAM, witch controls the system.
5-2 System Control Section
This circuit consists of the EP-ROM and SRAM, external Real Time Clock crystal, RTC and memory back-up
circuitry, and the Super Fax Chip (KS16118).
The KS16118 Super Fax Chip is an integrated 9600 bps modem, image processor, 8-bit MPU, peripheral
controller, and analog front end circuit on a single-chip.
Peripheral functions inculde 2-channel SI0, 3-channel DMA, 6-bit Half flash A/D converter, scanner and
video processor units, TPH interface, CODEC unit, and tone generator.
Modem is a 9600 bps, half duplex monolithic device incorporating digital filters, a Samsung SSP1600 digital
signal processor and CPU-Interface logic.
5-2-1 Memory Map
The external memory of the CPU is devided into, 1 byte(FF00H) DSP chip select, 32kbyte SRAM (0000H
through 7FFFH) and 128kbyte EP-ROM (0100H through 1FFFH).
1FFFH
0100H
00FFH
0000H
SF150T
/PMS
(EP-ROM)
Interrupt
Vectors
[ Program Memory ]
Figure 5-1: KS16118 External Memory Map
FFFFH
DSP /CS
PCS1
FF80H
FF7FH
Peripheral
PCS0
FF00H
FEFFH
/DMS
(SRAM)
0000H
[ Data Memory ]
5-1