mc68hc05jb4p Freescale Semiconductor, Inc, mc68hc05jb4p Datasheet - Page 39

• Manufacturer Part Number: mc68hc05jb4p
• Description: Mc68hc705jb4 Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

MC68HC05JB4
REV 2
RESET
V
This section describes the six reset sources and how they initialize the 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 vec-
tor address. The following conditions produce a reset:
Figure 5-1 shows a block diagram of the reset sources and their interaction.
DD
•
•
•
•
•
•
Initial power up of device (power on reset).
A logic zero applied to the RESET pin (external reset).
Timeout of the COP watchdog (COP reset).
Low voltage applied to the device (LVR reset).
Fetch of an opcode from an address not in the memory map (illegal
address reset).
Detection of USB reset signal (USB reset).
ILLEGAL ADDRESS RESET
USB RESET DETECTION
LOW VOLTAGE RESET
POWER-ON RESET
COP WATCHDOG
Freescale Semiconductor, Inc.
For More Information On This Product,
Figure 5-1. Reset Sources
Go to: www.freescale.com
INTERNAL
ADDRESS BUS
February 24, 1999
SECTION 5
RESETS
RESETS
GENERAL RELEASE SPECIFICATION
D
RESET
LATCH
S
R
RST
TO CPU
AND
SUBSYSTEMS
INTERNAL
CLOCK