MC68HC705JP7CDW Freescale Semiconductor, MC68HC705JP7CDW Datasheet - Page 43

• Manufacturer Part Number: MC68HC705JP7CDW
• Description: IC MCU 8BIT 28-SOIC
• Manufacturer: Freescale Semiconductor
• Series: HC05r

Specifications of MC68HC705JP7CDW

• Core Processor: HC05
• Core Size: 8-Bit
• Speed: 2.1MHz
• Connectivity: SIO
• Peripherals: POR, Temp Sensor, WDT
• Number Of I /o: 22
• Program Memory Size: 6KB (6K x 8)
• Program Memory Type: OTP
• Ram Size: 224 x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 4x12b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 28-SOIC (7.5mm Width)
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -

Chapter 5
Resets
5.1 Introduction
This section describes the five reset sources and how they 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:
Figure 5-1
Freescale Semiconductor
•
•
•
•
•
Initial power-up of device (power-on reset)
A logic 0 applied to the RESET pin (external reset)
Timeout of the computer operating properly (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)
RESET
V
DD
shows a block diagram of the reset sources and their interaction.
MASK OPTION REGISTER ($1FF1)
MC68HC705JJ7 • MC68HC705JP7 Advance Information Data Sheet, Rev. 4.1
ILLEGAL ADDRESS RESET
LOW-VOLTAGE RESET
POWER-ON RESET
COP WATCHDOG
CLOCKED
3-CYCLE
1-SHOT
Figure 5-1. Reset Sources
INTERNAL
ADDRESS BUS
INTERNAL DATA BUS
D
RESET
LATCH
S
R
RST
TO CPU
AND
SUBSYSTEMS
INTERNAL
CLOCK
43