Datasheet

Section 17 Keyboard Buffer Controller

Rev. 4.00 Sep 27, 2006 page 575 of 1130

REJ09B0327-0400

Receive data processing

Clear KBF flag

(KCLK = H)

Processing 1

Receive operation ends

normally

[1] On the system side, drive the KCLK pin low,

setting the I/O inhibit state.

[1]

Transmit enabled state.

If there is transmit data,

the data is transmitted.

Figure 17.7 Sample Receive Abort Processing Flowchart (cont)

Keyboard side monitors clock during

receive operation (transmit operation

as seen from keyboard), and aborts

receive operation during this period.

KCLK

(pin state)

KCLK

(input)

KCLK

(output)

(input)

(output)

Reception in progress Receive abort request

Transmit operation

Start bit

Figure 17.8 Receive Abort and Transmit Start (Transmission/Reception Switchover)

Timing