MC68HC705C9A_1 Datasheet, PDF (51/157 Pages) Freescale Semiconductor, Inc – General Release Specification

Freescale Semiconductor, Inc.
General Release Specification — MC68HC705C9A
Section 5. Resets
5.1 Contents
5.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .51
5.3 Power-On Reset (POR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .52
5.4 RESET Pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .52
5.5 Computer Operating Properly (COP) Reset . . . . . . . . . . . . . . .54
5.6 MC68HC05C9A Compatible COP . . . . . . . . . . . . . . . . . . . . . .54
5.6.1 C9A COP Reset Register . . . . . . . . . . . . . . . . . . . . . . . . . .55
5.6.2 C9A COP Control Register . . . . . . . . . . . . . . . . . . . . . . . . .56
5.7 MC68HC05C12A Compatible COP . . . . . . . . . . . . . . . . . . . . .58
5.8 MC68HC05C12A Compatible COP Clear Register . . . . . . . . .58
5.9 COP During Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .58
5.10 COP During Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .59
5.10.1 Clock Monitor Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .59
5.10.2 STOP Instruction Disable Option . . . . . . . . . . . . . . . . . . . .59
5.2 Introduction
The MCU can be reset four ways: by the initial power-on reset function,
by an active low input to the RESET pin, by the COP, or by the clock
monitor. A reset immediately stops the operation of the instruction being
executed, initializes some control bits, and loads the program counter
with a user-defined reset vector address. Figure 5-1 is a block diagram
of the reset sources.
MC68HC705C9A — Rev. 2.0
Resets
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