Canon Laser Class 810, Service Manual

Page: 85 / 322

Chapter 3
3-5
F-3-4
MPU (IC1)
Processes JBIG coding/decoding, controls combinations over lines, and controls SDRAM.
PATCH (IC40)
controls the various boards (NCU, speaker).
SDRAM
Controls coding/decoding of image data for transmission/reception, and stores data for the MPU work area and transmission/reception data.
MODEM IC (IC1)
For transmission, modulates data received from MPU according to ITU-T V.17, V21, V27ter, V29, or V.34; for reception, on the other hand, demodulates data
received from the line according to ITU-T V.17, V.21, V.27ter, V.29, or V.34.
Super Capacitor
Backs up the transmission/reception image data stored in SDRAM.
DC/DC
When the main power is off (e.g., in the event of power failure), increases the voltage of the super capacitor to generate a backup voltage for SDRAM.
SDRAM
Speaker
PATCH
(IC40)
MPU
(IC1)
MODEM IC
DX336
(IC1)
16
b
i
t
32bit
Speaker
driver
(IC70)
Image processor PCB
CU PCB
Modem PCB
Super
capacitor
DC/DC