Figure 17.7 (2) Sample Receive Abort Processing Flowchart; Figure 17.8 Receive Abort And Transmit Start (Transmission/Reception Switchover) - Renesas H8S Series Hardware Manual

Processing 1
Receive operation ends
normally
Receive data processing
Clear KBF flag
(KCLK = High)
Transmit enabled state.
If there is transmit data,
the data is transmitted.

Figure 17.7 (2) Sample Receive Abort Processing Flowchart

Reception in progress
KCLK
(pin state)
KD
(pin state)
KCLK
(input)
KCLK
(output)
KD
(input)
KD
(output)
[1]
Keyboard side monitors clock during
receive operation (transmit operation
as seen from keyboard), and aborts
receive operation during this period.
Receive abort request
Figure 17.8 Receive Abort and Transmit Start
(Transmission/Reception Switchover) Timing
Section 17 Keyboard Buffer Control Unit (KBU)
[1] On the system side, drive the KCLK pin low,
setting the I/O inhibit state.
Transmit operation
Rev. 3.00 Jul. 14, 2005 Page 599 of 986
Start bit
REJ09B0098-0300