MC68HC705X32CFU Freescale Semiconductor, MC68HC705X32CFU Datasheet - Page 137

• Manufacturer Part Number: MC68HC705X32CFU
• Manufacturer: Freescale Semiconductor

Specifications of MC68HC705X32CFU

• Cpu Family: HC05
• Device Core Size: 8b
• Frequency (max): 4MHz
• Interface Type: SCI
• Program Memory Type: EPROM
• Program Memory Size: 32KB
• Total Internal Ram Size: 528Byte
• # I/os (max): 32
• Number Of Timers - General Purpose: 1
• Operating Supply Voltage (typ): 5V
• Operating Supply Voltage (max): 5.5V
• Operating Supply Voltage (min): 4.5V
• On-chip Adc: 8-chx8-bit
• Instruction Set Architecture: CISC
• Operating Temp Range: -40C to 85C
• Operating Temperature Classification: Industrial
• Mounting: Surface Mount
• Pin Count: 64
• Package Type: PQFP
• Lead Free Status / Rohs Status: Supplier Unconfirmed

10.1.3
When the oscillator is running in a stable condition, the MCU is reset when a logic zero is applied
to the RESET input for a minimum period of 1.5 machine cycles (t
is used to improve noise immunity on this pin. When the RESET pin goes high, the MCU will
resume operation on the following cycle. When a reset condition occurs internally, i.e. from POR
or the COP watchdog, the RESET pin provides an active-low open drain output signal which may
be used to reset external hardware. Current limitation to protect the pull-down device is provided
in case an RC type external reset circuit is used.
Note:
10.1.4
The watchdog counter system consists of a divide-by-7 counter, preceded by a fixed divide-by-4
and a fixed divide-by-256 prescaler, plus control logic as shown in
counter can be reset by software.
Note:
MC68HC05X16
If an external RC is connected to RESET, turning on the RESET pull-down transistor
may discharge the capacitor. The device will then remain in reset until the capacitor has
recharged, after turning off the pull-down device.
The input to the watchdog system is derived from the carry output of bit 7 of the free
running timer counter. Therefore, a reset of the timer may affect the period of the
watchdog timeout.
RESET pin
Computer operating properly (COP) watchdog reset
Freescale Semiconductor, Inc.
For More Information On This Product,
Figure 10-2 RESET external RC pull-down
Go to: www.freescale.com
RESETS AND INTERRUPTS
RESET
VDD
pin
pin
MC68HC05X16
CYC
Figure
). An internal Schmitt Trigger
10-3. The divide-by-7
10-3
10