Oki PACEMARK 4410, Service Handbook

Page: 29 / 189

40496501TH Draft Version
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2.1.13 Operation Panel
The clock synchronization OPCLK of NHDC LSI is used to input the switch data and output the LED
data and LCD data through the operation panel control LSI (IC1: BU6152S).
A 2-byte (15 bits + 1 even parity bit) command (OPDATAOUT-P) is transmitted to the LSI
(BU6152S) in synchronization with the OPSCLK-N signal. The LSI decodes this command and
when it is found to be legal, returns a 2-byte command response back to the NHDC LSI which
includes data on Switch information, LED status, LCD 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
OPSQCR-N signal.
NHDC LSI
BU6152S
OPDATAOUT-P
OPSCLK-N
OPSQCR-N
OPDATAIN-P
56
59
58
SDO
SCKN
SCSN
SDI
Command
and Data
latch
LED driver
Switch
controller
+5V
57
Figure 2.17