Oki ML421 Maintenance Manual - Page 25

Operation Panel

Page 25 highlights

Oki Data CONFIDENTIAL 2.1.7 Operation Panel The clock synchronization OPCLK of LSI is used to input the switch data and output the LED data through the operation panel control IC. LSI OPTD OPCK NPA2 OPRD OPTXD 48 OPCLK 47 OPCLR-N 45 OPRXD 46 Operation panel control IC Command and Data latch LED driver +5V Switch controller A 2-byte (15 bits + 1 even parity bit) command (OPTXD) is transmitted to the Operation panel control IC in synchronization with the OPCLK signal. The Operation panel control IC decodes this command and when it is found to be legal, returns a 2-byte command response back to the LSI which includes data on Switch information, LED status, receive command ACK/NAK and 1 odd parity bit. Any transmission errors found cause the command to be reissued after the transmission of the OPCLR-N signal. 42113901 Rev.2 25 /

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42113901
Rev.2
25 /
Oki
Data
CONFIDENTIAL
LSI
Operation panel control IC
OPTXD
OPCLK
OPCLR-N
OPRXD
48
47
45
OPTD
OPCK
NPA2
OPRD
Command
and Data
latch
LED driver
Switch
controller
+5V
46
2.1.7
Operation Panel
The clock synchronization OPCLK of LSI is used to input the switch data and output the LED
data through the operation panel control IC.
A 2-byte (15 bits + 1 even parity bit) command (OPTXD) is transmitted to the Operation panel
control IC in synchronization with the OPCLK signal. The Operation panel control IC decodes
this command and when it is found to be legal, returns a 2-byte command response back to
the LSI which includes data on Switch information, LED status, receive command ACK/NAK and
1 odd parity bit.
Any transmission errors found cause the command to be reissued after the transmission of the
OPCLR-N signal.