Ricoh A250 Service Manual page 442

2.6 PCBS
2.6.1 FCU
ISDN
V.34 MODEM
Analog Circuit
N C U
Monitor
Speaker
Bus Interface
Parallel Interface
The FCU (Facsimile Control Unit) controls fax communications, the video interface
to the base copier's engine, and all the fax options.
FACE
• CPU
• Data compression and reconstruction (DCR)
• DMA control
• Clock generation
• DRAM backup control
• Ringing signal/tone detection
• Video and command interface to the BiCU (VIF)
SM
FCU
S R A M Flash ROM
(128kB) (2MB)
CPU BUS
FACE
CPU (RU30) D C R
DMA BUS
E X F U N C E X M E M
Board Board
(512kB) (32MB)
2-21
PCBS
VIF BiCU
D R A M
(8MB)
A891V500.WMF
A250