Canon FAX-L1000 - Manual (Page 516)

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FAX-L1000 Chapter 5: Appendix
e) PCM CODEC IC (IC50)
This IC converts receive signals (digital signals through ISDN lines) to analog signals. It
converts transmit signals (analog audio signals) to digital signals.
f) Slave CPU (IC21)
The slave CPU, NEC-made uPD70F3025AGC-33 (V.853), converts encode data (MH, MR,
MMR, JBIG, etc.) from the transmit circuit to encode data (MR) for the SCNT board in
receive mode. The CPU converts encode data (MR) from the SCNT board to encode data
(MH, MR, MMR, JBIG, etc.) suitable for the remote machine.
g) Main CPU (IC8)
The main CPU, NEC-made uPD70741GC-25-TEA (V.821), controls operations in the same
way as the CPU (IC17) on the SNCT board.
h) System controller (IC20)
The system controller, MITSUBISHI-made M66364FP, is a standard cell that controls
peripheral devices for the MPU. It contains peripheral IC chip select, DRAM control, and
DMA controller.
i) ROM (IC1)
The 1M-byte ROM contains a transmission control (V.821) program.
j) DRAM (IC41)
The 1M-byte DRAM is used to store image data in transmit and receive modes and as a
work area for the CPU.
k) TWINS IC (IC39)
This NEC-made gate-array UPD65802GJ-117-3EN controls the IEEE1284’s dual-party
transmission port.
l) Parallel/serial conversion IC (IC10)
The parallel/serial conversion IC, HITACHI-made HD64570F16, converts serial signals
from a modem to parallel signals in G3 transmission. It converts serial signals from an
ISDN line to parallel signals in G4 transmission.