MC68HC705C Motorola, MC68HC705C Datasheet - Page 59

• Manufacturer Part Number: MC68HC705C
• Description: HCMOS Microcontroller Unit
• Manufacturer: Motorola

5.1 Contents
5.2 Introduction
5.3 Reset Sources
MC68HC705C8A — Rev. 2.0
MOTOROLA
Technical Data — MC68HC705C8A
5.2
5.3
5.3.1
5.3.2
5.3.3
5.3.3.1
5.3.3.2
5.3.4
This section describes how resets initialize the microcontroller unit
(MCU).
A reset immediately stops the operation of the instruction being
executed, initializes certain control bits, and loads the program counter
with a user-defined reset vector address. These conditions produce a
reset:
•
•
•
•
•
Power-on reset (POR) — Initial power-up
External reset — A logic 0 applied to the RESET pin
Internal programmable computer operating properly (COP)
watchdog timer reset
Internal non-programmable COP watchdog timer reset
Internal clock monitor reset
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .59
Reset Sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .59
Power-On Reset (POR) . . . . . . . . . . . . . . . . . . . . . . . . . . . .60
External Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .60
Programmable and Non-Programmable
Clock Monitor Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .65
Programmable COP Watchdog Reset . . . . . . . . . . . . . . .61
Non-Programmable COP Watchdog . . . . . . . . . . . . . . . .64
COP Watchdog Resets . . . . . . . . . . . . . . . . . . . . . . . . . .60
Resets
Section 5. Resets
Technical Data
59