Renesas H8S/2111B 用户手册

Rev. 1.00, 05/04, page 364 of 544 

 

In this device, clearing the KBFSEL bit to 0 in KBCRH enables the KBF bit in KBCRL to be used 
as a flag for the interrupt generated by the fall of KCLK input. 

Figure 14.13 shows the setting method and an example of operation. 

Start

Set KBIOE

KBF = 1

(interrupt generated)

KBE = 0

(KBBR reception

disabled)

Interrupt handling

 Clear KBF

KCLK pin

fall detected?

KBFSEL = 0

KBIE = 1

 (KCLK falling edge

interrupts enabled)

Yes

No

KCLK
(pin state)

KBF bit

Interrupt
generated

Interrupt
generated

Cleared 
by software

Note:  *   The KBF setting timing is the same as the timing of KBF setting and KCLK automatic I/O inhibit bit generation in 

figure 14.11. When the KBF bit is used as the KCLK input fall interrupt flag, the automatic I/O inhibit function does 

not operate.