mc68hc05ct4fn Freescale Semiconductor, Inc, mc68hc05ct4fn Datasheet - Page 50

• Manufacturer Part Number: mc68hc05ct4fn
• Description: Mc68hc05 Family Of Microcontrollers Mcus
• Manufacturer: Freescale Semiconductor, Inc

Operating Modes
6.3 Single-Chip Mode
6.4 Low-Power Modes
6.4.1 Stop Mode
General Release Specification
In single-chip mode, the address and data buses are not available
externally, but there are three 8-bit input/output (I/O) ports and one 7-bit
I/O port. This mode allows the MCU to function as a self-contained
microcontroller, with maximum use of the pins for on-chip peripheral
functions. All address and data activity occurs within the MCU. Single-
chip mode is entered on the rising edge of RESET if the IRQ pin is within
normal operating range.
The following paragraphs describe the low-power modes.
The STOP instruction places the MCU in its lowest power-consumption
mode. In stop mode, the internal oscillator is turned off, halting all
internal processing, including timer operation.
During stop mode, the CTCSR ($08) bits are altered to remove any
pending timer interrupt request and to disable any further timer
interrupts. The timer prescaler is cleared. The I bit in the CCR is cleared
to enable external interrupts. All other registers and memory remain
unaltered. All input/output lines remain unchanged. The processor can
be brought out of stop mode only by an external interrupt or reset.
Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
Operating Modes
MC68HC05CT4
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Rev. 2.0