HD64F2149 Datasheet, PDF (569/1035 Pages) Renesas Technology Corp – Hitachi 16-Bit Single-Chip Microcomputer

Bit 5—Keyboard Data In (KDI): Monitors the KDI I/O pin. This bit cannot be modified.
Bit 5
KDI
0
1
Description
KD I/O pin is low
KD I/O pin is high
(Initial value)
Bit 4—Keyboard Buffer Register Full Select (KBFSEL): Selects whether the KBF bit is used
as the keyboard buffer register full flag or as the KCLK fall interrupt flag, When KBFSEL is
cleared to 0, the KBE bit in the KBCRL register should be cleared to 0 to disable reception.
Bit 4
KBFSEL
0
1
Description
KBF bit is used as KCLK fall interrupt flag
KBF bit is used as keyboard buffer register full flag
(Initial value)
Bit 3—Keyboard Interrupt Enable (KBIE): Enables or disables interrupts from the keyboard
buffer controller to the CPU.
Bit 3
KBIE
0
1
Description
Interrupt requests are disabled
Interrupt requests are enabled
(Initial value)
Bit 2—Keyboard Buffer Register Full (KBF): Indicates that data reception has been completed
and the received data is in the keyboard data buffer register (KBBR).
Bit 2
KBF
0
1
Description
[Clearing condition]
(Initial value)
Read KBF when KBF =1, then write 0 in KBF
[Setting condition]
• When data has been received normally and has been transferred to KBBR
(keyboard buffer register full flag)
• When a KCLK falling edge is detected (while KBFSEL = 0) (KCLK interrupt flag)
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