MAIN PCBS AND THEIR FUNCTIONS
16 February 2000
2-28
2.8.2 SCU (SCANNER CONTROL UNIT)
This is the main board. The functions of each component are as follows.
CPU: HD6413002F
•
Scanner sequence control
•
Clock/timer control
•
DMA control
IPU (Image Processing Unit):
•
Shading correction
•
Image processing (Mirror image, reproduction ratios, MTF correction, binary
picture processing, edge extraction, and so on)
Memory Controller:
•
Stores the image data from the IPU in the memory (DRAM 32 Mbytes x 2).
•
Address control when recalling the data from the memory.
SCSI controller: SCSI interface controller.
SRAM: Work area (32 kbytes)
EPROM: Contains the program.
Enhanced I/O (EIO):
•
Extension for the I/O port.
•
DIP switches (mode selection), rotary switches (SCSI ID setting), and a push
switch (reset button) are connected.
E
2
PROM: Holds the book, ADF, and lamp counter values.
I P U
S C S I
Controller
E P R O M
4 Mbit (x16)
S R A M
2 5 6 kbit (x8)
E
2
P R O M
2 kbit
Reset IC
C P U
E I O
SCSI ID
Rotary
S W
D I P S W
S C S I
Terminator
O S C
O S C
D R A M
16 Mbit (x16)
O d d
E v e n
C P U B u s
O S C
V R S
E R C U
IOB
SCSI 1
SCSI 2
S C U
Image data
Signal line
S E L
M e m o r y
Controller
G413D512.WMF
