Keyboard Interrupt Module (KBI)
Technical Data MC68HC908AB32 — Rev. 1.0
346 Keyboard Interrupt Module (KBI) MOTOROLA
19.3 Features
Features of the keyboard interrupt module include the following:
• Five keyboard interrupt pins with pullup devices
• Separate keyboard interrupt enable bits and one keyboard
interrupt mask
• Built-in pull-up device if input pin is configured as input port bit
• Programmable edge-only or edge- and level- interrupt sensitivity
• Exit from low-power modes
19.4 I/O Pins
The five keyboard interrupt pins are shared with standard port I/O pins.
The full name of the KBI pins are listed in Table 19-1. The generic pin
name appear in the text that follows.
Addr. Register Name Bit 7 654321Bit 0
$001B
Keyboard Status
and Control Register
(KBSCR)
Read: 0000KEYF 0
IMASKK MODEK
Write: ACKK
Reset: 00000000
$0021
Keyboard Interrupt Enable
Register (KBIER)
Read: 0 0 0
KBIE4 KBIE3 KBIE2 KBIE1 KBIE0
Write:
Reset: 00000000
= Unimplemented
Figure 19-1. KBI I/O Register Summary
Table 19-1. Pin Name Conventions
KBI
Generic Pin Name
Full MCU Pin Name
Pin Selected for KBI Function by
KBIEx Bit in KBIER
KBD0 PTG0/KBD0 KBIE0
KBD1 PTG1/KBD1 KBIE1
KBD2 PTG2/KBD2 KBIE2
KBD3 PTH0/KBD3 KBIE3
KBD4 PTH1/KBD4 KBIE4