Renesas H8S/2111B - Manual (Page 394)

Rev. 1.00, 05/04, page 360 of 544
Receive data processing
Clear KBF flag
(KCLK = High)
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 14.7 Sample Receive Abort Processing Flowchart (2)
Keyboard side monitors clock during
receive operation (transmit operation
as seen from keyboard), and aborts
receive operation during this period.
KCLK
(pin state)
KD
(pin state)
KCLK
(input)
KCLK
(output)
KD
(input)
KD
(output)
Reception in progress Receive abort request
Transmit operation
Start bit
Figure 14.8 Receive Abort and Transmit Start
(Transmission/Reception Switchover) Timing