mc68hc912dg128 Freescale Semiconductor, Inc, mc68hc912dg128 Datasheet - Page 147

• Manufacturer Part Number: mc68hc912dg128
• Description: M68hc12 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

Technical Data — MC68HC912DG128
10.1 Contents
10.2 Introduction
MC68HC912DG128 — Rev 3.0
MOTOROLA
10.2
10.3
10.4
The MC68HC912DG128 offers 16 additional I/O ports with key wake-up
capability.
The key wake-up feature of the MC68HC912DG128 issues an interrupt
that will wake up the CPU when it is in the STOP or WAIT mode. Two
ports are associated with the key wake-up function: port H and port J.
Port H and port J wake-ups are triggered with a rising or falling signal
edge. For each pin which has an interrupt enabled, there is a path to the
interrupt request signal which has no clocked devices when the part is in
stop mode. This allows an active edge to bring the part out of stop.
Digital filtering is included to prevent pulses shorter than a specified
value from waking the part from STOP.
An interrupt is generated when a bit in the KWIFH or KWIFJ register and
its corresponding KWIEH or KWIEJ bit are both set. All 16 bits/pins share
the same interrupt vector. Key wake-ups can be used with the pins
configured as inputs or outputs.
Default register addresses, as established after reset, are indicated in
the following descriptions. For information on re-mapping the register
block, refer to
Freescale Semiconductor, Inc.
For More Information On This Product,
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147
Key Wake-up and Port Registers . . . . . . . . . . . . . . . . . . . . . .148
Key Wake-Up Input Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152
Section 10. I/O Ports with Key Wake-up
I/O Ports with Key Wake-up
Go to: www.freescale.com
Operating
Modes.
Technical Data
147