Datasheet

Section 17 Keyboard Buffer Controller
Rev. 4.00 Sep 27, 2006 page 564 of 1130
REJ09B0327-0400
Bit 5—Keyboard Data In (KDI): Monitors the KDI I/O pin. This bit cannot be modified.
Bit 5
KDI Description
0 KD I/O pin is low
1 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 Description
0 KBF bit is used as KCLK fall interrupt flag
1 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 Description
0 Interrupt requests are disabled (Initial value)
1 Interrupt requests are enabled
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 Description
0 [Clearing condition] (Initial value)
Read KBF when KBF =1, then write 0 in KBF
1 [Setting conditions]
• 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)