Samsung SCX-1100 Service Manual page 84

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Image Processing Section(IP)
After performing color compensating required for the
System for RGB digital data input, it conducts the role of
converting to CMYK data printable. IP Block consists of four
Modules mainly.
- Photo text detect
- Zoom and dpi adjust
- Color space conversion
- Half toning and loss less JPEG
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Memory Interface Section(MI)
MI Block consists of four Channels, located between exter-
nal SDRAM(U27) and blocks inside OA-980, and is con-
trolled so that the flow of all data may be accomplished more
efficiently.
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JBIG Comp & Decomp Section
By condensing Image data processed at Blocks into JBIG
algorithm and save them in external SDRAM(U27), it shall
have Memory domain used more efficiently. Naturally, even
when moving Image data which was condensed to JBIG, to
other block, it is conveyed to Image data freed from conden-
sation.
Samsung Electronics
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After Image CMYK Data which ended all image processing
is converted to Format so that Inkjet Printer Engine may
print, it plays the role of saving them on the external
SDRAM(U27).
The Data stored in the external SDRAM(U27) is transferred
to Head Control Part of Jupiter3 through MI and HI Block of
OA-980 by DMA of Jupiter3, and then printed by Spitfire.
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When the Image process required for PC Scan (See Fig.
19) is completed, OA-980 requests that /IP_REQ signal in
PO_Block should take the Scan Image Data from the
External DMA Block of Jupiter3(U15). The External DMA
Block of Jupiter3(U15) generates not only /IP_ACK signal
to bring Data by Byte as the unit but also /RD signal to bring
the Data. The External DMA Block of Jupiter3(U15) stores
the Data in SDRAM(U9) and then restore /IP_ACK as
"High" to receive a next Data/.
As DMA Timing properties between Jupiter and OA-980 do
not match, /IP_ACK0 is separately created to prevent BUS
collision by using one OR-Gate(U18-3) so that OA-980 may
use the BUS only in /RD in the way of inputting the /ACK
signal into OA-980 only when /RD is actually produced,
while Jupiter3 may use in /WR, as shown in the Timing of
Fig. 18. That is, since OA-980 sends Data to BUS during
/ACK signal section, BUS collision occurs between DMA of
Jupiter3 and /WR section, where /RD, /WR are all carried
out during /ACK.
<Figure 18. PO Block DMA Timing Diagram>
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CIRCUIT DESCRIPTION
Rotate and Inkjet Engine Section
Printer Interface Section(PO)
Repair Manual
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