MC68HC812A4 Datasheet, PDF (143/342 Pages) Motorola, Inc – 16-bit device composed of standard on-chip peripheral modules connected by an intermodule bus. Modules include

Advance Information — MC68HC812A4
Section 9. Key Wakeups
9.1 Contents
9.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .143
9.3 Key Wakeup Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .144
9.3.1 Port D Data Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . .144
9.3.2 Port D Data Direction Register . . . . . . . . . . . . . . . . . . . . . .145
9.3.3 Port D Key Wakeup Interrupt Enable Register . . . . . . . . . .145
9.3.4 Port D Key Wakeup Flag Register . . . . . . . . . . . . . . . . . . .146
9.3.5 Port H Data Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . .146
9.3.6 Port H Data Direction Register . . . . . . . . . . . . . . . . . . . . . .147
9.3.7 Port H Key Wakeup Interrupt Enable Register . . . . . . . . . .147
9.3.8 Port H Key Wakeup Flag Register . . . . . . . . . . . . . . . . . . .148
9.3.9 Port J Data Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .148
9.3.10 Port J Data Direction Register . . . . . . . . . . . . . . . . . . . . . .149
9.3.11 Port J Key Wakeup Interrupt Enable Register . . . . . . . . . .149
9.3.12 Port J Key Wakeup Flag Register . . . . . . . . . . . . . . . . . . .150
9.3.13 Port J Key Wakeup Polarity Register . . . . . . . . . . . . . . . . .150
9.3.14 Port J Pullup/Pulldown Select Register . . . . . . . . . . . . . . .151
9.3.15 Port J Pullup/Pulldown Enable Register. . . . . . . . . . . . . . .152
9.2 Introduction
The key wakeup feature of the MC68HC812A4 issues an interrupt that
wakes up the CPU when it is in stop or wait mode. Three ports are
associated with the key wakeup function: port D, port H, and port J. Port
D and port H wakeups are triggered with a falling signal edge. Port J key
wakeups have a selectable falling or rising signal edge as the active
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.
Advance Information
MOTOROLA
Key Wakeups
MC68HC812A4 — Rev. 3.0
143