MC9RS08KA2_08 Datasheet, PDF (53/136 Pages) Freescale Semiconductor, Inc – RS08 Microcontrollers

Chapter 7 Keyboard Interrupt (RS08KBIV1)
7.3 Register Definition
The KBI includes three registers:
• An 8-bit pin status and control register
• An 8-bit pin enable register
• An 8-bit edge select register
Refer to the direct-page register summary in Chapter 4, “Memory,” for the absolute address assignments
for all KBI registers. This section refers to registers and control bits only by their names.
The KBI registers are summarized in Table 7-2.
Table 7-2. KBI Register Summary
Name
KBISC
KBIPE
KBIES
7
R
0
W
R
0
W
R
0
W
6
5
4
3
2
1
0
0
0
0
KBF
0
KBIE KBMOD
KBACK
0
0
KBIPE5 KBIPE4
KBIPE2 KBIPE1 KBIPE0
0
0
KBEDG5 KBEDG4
KBEDG2 KBEDG1 KBEDG0
7.3.1 KBI Status and Control Register (KBISC)
KBISC contains the status flag and control bits, which are used to configure the KBI.
7
6
5
4
3
2
1
0
R
0
0
0
0
KBF
0
KBIE
KBMOD
W
KBACK
Reset:
0
0
0
0
0
0
0
0
= Unimplemented
Figure 7-3. KBI Status and Control Register (KBISC)
Table 7-3. KBISC Register Field Descriptions
Field
Description
3
KBF
2
KBACK
Keyboard Interrupt Flag — KBF indicates that a keyboard interrupt is detected. Writes have no effect on KBF.
0 No keyboard interrupt detected.
1 Keyboard interrupt detected.
Keyboard Acknowledge — Writing a 1 to KBACK is part of the flag-clearing mechanism. KBACK always reads
as 0.
MC9RS08KA2 Series Data Sheet, Rev. 4
Freescale Semiconductor
53