Oki PACEMARK 4410 Service Manual page 18

(6) Main LSI (IC38: MSM91U036)
MSM91U036 is control LSI for head data, DC motor and modification of print data, which has
the following functions.
(a) Head data control
It distributes print data stored in the DRAM over wire arrangements of the print head and
outputs it as dot data in synchronism with print timing. In this time, the distribution
complies with each print mode which is specified by the MPU.
(b) Print timing control
It outputs the signals which control the print timing of ODD and EVEN pins on the print
head.
(c) Space motor speed control function
It controls the space motor with micro-programs to accelerate/decelerate it.
This LSI also controls the speed of the space motor in agreement with each print mode.
(d) I/O port
This printer has 8-bit output port which is used for controlling the SRAM.
(e) Head position count
It counts the outputs from slit sensors (SPPHASE A, B) located on the space motor to
keep monitoring the current position of the print head.
(f) Print data modifying function
It modifies the print data stored in the DRAM with command inputs from the MPU.
(g) DMA control function
It outputs a DMA request to the MPU, simultaneously controlling the DMA.
This LSI is connected in multiplex to the MPU.
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