Computer Hardware User Manual

MC68HC05RC16 — Rev. 3.0 General Release Specification
MOTOROLA Resets 45
General Release Specification — MC68HC05RC16
Section 5. Resets
5.1 Contents
5.2 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45
5.3 External Reset (RESET). . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46
5.4 Low-Power External Reset (LPRST) . . . . . . . . . . . . . . . . . . . .48
5.5 Internal Resets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48
5.5.1 Power-On Reset (POR). . . . . . . . . . . . . . . . . . . . . . . . . . . .48
5.5.2 Computer Operating Properly Reset (COPR) . . . . . . . . . . .49
5.5.2.1 Resetting the COP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .49
5.5.2.2 COP During Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . .49
5.5.2.3 COP During Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . .49
5.5.2.4 COP Watchdog Timer Considerations. . . . . . . . . . . . . . .50
5.5.2.5 COP Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .51
5.5.3 Illegal Address. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .51
5.2 Introduction
The MCU can be reset from five sources: two external inputs and three
internal restart conditions. The
RESET and LPRST pins are inputs as
shown in Figure 5-1. All the internal peripheral modules will be reset by
the internal reset signal (RST). Refer to Figure 5-2 for reset timing detail.