Asic - Sharp AL-1000 Service Manual

(2) ASIC

1. Outline
Fig. 4 shows the block diagram of the ASIC.
The ASIC is composed of the following three blocks; the image process section, the print control section, and the I/F section.
The image process section processes the image data from the CCD PWB according to the operation mode, such as shading, AE
process, resolution conversion. and zooming.
The print control section outputs the image-processed data during copying to the LSU (Laser unit) in synchronization with writing
timing of the LSU.
The I/F section controls communication of interface (IEEE1284) with the host PC and controls DRAM of send/receive data buffer with
the host PC. (Only for models with the printer function)
The ASIC is controlled by the CPU which writes the operation mode and the set values necessary for each operation mode to the
ASIC control register.
ASIC
Scan start
Image process section
CCD
PWB
SRAM control
SRAM
32KB
x 2
Print control section
Resolution conversion,
Zooming, lmage
process circuit
Print data process circuit
PRINT control
IEEE1284 control
DRAM control
ASIC control resistor
I/F section
DRAM
6MB or 4MB
12-6
AL-1000/1010
LSU
HSYNC
VSYNC
TO PCI/F
PWB
(Only for models
withthe printer
function)
To CPU bus