OKIDATA MICROLINE 320, Service Manual

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2.1.3 Initialization
This printer is initialized when the power is turned on or when the I-PRIME-N signal is input
from the host side via the parallel interface.
For the initialize operation, the RST-N signal is first output from the reset circuit to reset the
MPUs and LSIs. When resetting ends, the program starts and the LSIs are reset by MPU via
LSIRST-N. Reset operation by I-PRIME starts the program to initialize, but does not reset the
MPU.
The program sets the mode of the LSI including the MPU, checks the memories (ROMs and
RAMs), then carries out carriage homing, and determines the LF motor phase.
Finally, the program establishes the interface signals (P-I/F: ACK-P signal sending, and S-I/F:
BUSY-N signal off) and lights the SELECT lamp. When the ready state is set, the host is informed
that the printer is ready to receive data.
End
I/F BUSY OFF
Serial
I/F
I/F ACK Send
Parallel
I/F
LF Motor Phase
Initialization
Carriage Homing
RAM Clear
LSI Initial Setting
and I/F Busy ON
External RAM
CHECK
LSI RESET
ROM CHECK
Internal RAM
CHECK
MPU
Initial Setting
MPU RESET
Start