Logic Board Components - Canon S600 Service Manual

S600

4. LOGIC BOARD COMPONENTS

Stepping Motor Driver IC
a) Printer controller (IC101)
The printer controller has the following eight functions. It operates with a 48 MHz
external clock (not synchronized with the CPU).
1. I/F control
The data is transferred with a serial (USB 1.1 standard) or parallel (IEEE 1274
standard) transmission. Parallel transmissions operate in the compatible, nibble,
and ECP modes.
2. Receiving buffer control
The ring buffer-type receiving buffer and the straight-type transmission buffer are
controlled.
3. System management enabled
With the built-in timer, any clock stoppage or suction time is counted. Also the
status of the port in the printer controller is sampled.
4. Data decompression
The data compressed by the printer driver is restored as print data. In addition,
during printing in the HS mode, 300 dpi data is expanded by 2 vertically and
horizontally to 600 dpi. The CMY 2-bit data is also distributed to the even/odd
buffers for each even/odd array on the print head.
5. Data processing
A dot count is executed for power monitoring and smear processing. Also, dot
thinning for seam stripe processing is based on the dot count and color tone.
6. Printing control
The data received is rearranged in the raster direction.
Also, data is processed so that the print head's heaters are heated in the suitable
sequence.
Printer Controller
DC Motor Driver IC
Figure 3-12 Control Board
3-19
Part 3: Technical Reference
Control ROM
MPU
DRAM EEPROM