MC68HC908JW32_09 Datasheet, PDF (195/232 Pages) Freescale Semiconductor, Inc – M68HC08 Microcontrollers

Low-Power Modes
15.5.2 Keyboard Interrupt Enable Register
The keyboard interrupt enable register enables or disables each port A pin to operate as a keyboard
interrupt pin.
Address: $0017
Bit 7
6
5
4
3
2
1
Read:
KBIE7
Write:
KBIE6
KBIE5
KBIE4
KBIE3
KBIE2
KBIE1
Reset: 0
0
0
0
0
0
0
Figure 15-4. Keyboard Interrupt Enable Register (KBIER)
Bit 0
KBIE0
0
KBIE7–KBIE0 — Keyboard Interrupt Enable Bits
Each of these read/write bits enables the corresponding keyboard interrupt pin to latch interrupt
requests. Reset clears the keyboard interrupt enable register.
1 = PTAx pin enabled as keyboard interrupt pin
0 = PTAx pin not enabled as keyboard interrupt pin
15.6 Low-Power Modes
The WAIT and STOP instructions put the MCU in low-power consumption standby modes.
15.6.1 Wait Mode
The keyboard module remains active in wait mode. Clearing the IMASKK bit in the keyboard status and
control register enables keyboard interrupt requests to bring the MCU out of wait mode.
15.6.2 Stop Mode
The keyboard module remains active in stop mode. Clearing the IMASKK bit in the keyboard status and
control register enables keyboard interrupt requests to bring the MCU out of stop mode.
15.7 Keyboard Module During Break Interrupts
The system integration module (SIM) controls whether the keyboard interrupt latch can be cleared during
the break state. The BCFE bit in the break flag control register (BFCR) enables software to clear status
bits during the break state.
To allow software to clear the keyboard interrupt latch during a break interrupt, write a logic 1 to the BCFE
bit. If a latch is cleared during the break state, it remains cleared when the MCU exits the break state.
To protect the latch during the break state, write a logic 0 to the BCFE bit. With BCFE at logic 0 (its default
state), writing to the keyboard acknowledge bit (ACKK) in the keyboard status and control register during
the break state has no effect. (See Figure 15-3. Keyboard Status and Control Register (KBSCR).)
MC68HC908JW32 Data Sheet, Rev. 6
Freescale Semiconductor
195