42113901 Rev.2 25 /Oki Data CONFIDENTIALLSI Operation panel control ICOPTXDOPCLKOPCLR-NOPRXD484745OPTDOPCKNPA2OPRDCommandand DatalatchLED driverSwitchcontroller+5V462.1.7 Operation PanelThe clock synchronization OPCLK of LSI is used to input the switch data and output the LEDdata through the operation panel control IC.A 2-byte (15 bits + 1 even parity bit) command (OPTXD) is transmitted to the Operation panelcontrol IC in synchronization with the OPCLK signal. The Operation panel control IC decodesthis command and when it is found to be legal, returns a 2-byte command response back tothe LSI which includes data on Switch information, LED status, receive command ACK/NAK and1 odd parity bit.Any transmission errors found cause the command to be reissued after the transmission of theOPCLR-N signal.
