MC68HC908MR16/MC68HC908MR32
—
Rev. 5.0
Advance Information
MOTOROLA
Computer Operating Properly (COP)
325
Advance Information
—
MC68HC908MR16/MC68HC908MR32
Section 16. Computer Operating Properly (COP)
16.1 Contents
16.2
16.3
Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .325
Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .326
16.4
16.4.1
16.4.2
16.4.3
16.4.4
16.4.5
16.4.6
16.5
16.6
I/O Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .327
CGMXCLK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .327
COPCTL Write . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .327
Power-On Reset. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .327
Internal Reset. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .328
Reset Vector Fetch. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .328
COPD (COP Disable). . . . . . . . . . . . . . . . . . . . . . . . . . . . .328
COP Control Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .328
Interrupts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .328
16.7
16.8
16.9
Monitor Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .329
Wait Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .329
Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .329
16.2 Introduction
This section describes the computer operating properly module, a
free-running counter that generates a reset if allowed to overflow. The
computer operating properly (COP) module helps software recover from
runaway code. Prevent a COP reset by periodically clearing the COP
counter.