MC68HC05P18A Datasheet, PDF (50/130 Pages) Freescale Semiconductor, Inc – HCMOS Microcontroller Unit

Operating Modes
Freescale Semiconductor, Inc.
6.3 User Mode
The user 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 and is not
available externally. User mode is entered on the rising edge of RESET
if the IRQ pin is within the normal operating voltage range.
In the user mode, there is:
• An 8-bit input/output (I/O) port
• A second 8-bit I/O port shared with the analog-to-digital (A/D)
subsystem
• One 3-bit I/O port shared with the serial input/output port (SIOP)
• One 2-bit I/O port shared with the 16-bit timer subsystem
6.4 Low-Power Modes
The MC68HC05P18A is capable of running in a low-power mode in each
of its configurations. The WAIT and STOP instructions provide three
modes that reduce the power required for the MCU by stopping various
internal clocks and/or the on-chip oscillator. The STOP and WAIT
instructions are not normally used if the computer operating properly
(COP) watchdog timer is enabled. The stop conversion mask option is
used to modify the behavior of the STOP instruction from stop mode to
halt mode. The flow of the stop, halt, and wait modes is shown in
Figure 6-1.
Technical Data
Operating Modes
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MC68HC05P18A