Freescale Semiconductor, Inc.
Operating Modes and On-Chip Memory
3.3.1 Single chip operating mode
In single chip operating mode, the MC68HC11P2 microcontroller has no
external address or data bus. Ports B, C, F, and the R/W pin are
available for general-purpose parallel I/O.
3.3.2 Expanded operating mode
In expanded operating mode, the MCU can access a 64kbyte physical
address space. The address space includes the same on-chip memory
addresses used for single chip mode, in addition to external memory and
peripheral devices.
The expansion bus is made up of ports B, C, and F, and the R/W signal.
In expanded mode, high order address bits are output on the port B pins,
low order address bits on the port F pins, and the data bus on port C. The
R/W/PG7 pin signals the direction of data transfer on the port C bus.
3.3.3 Special test mode
Special test, a variation of the expanded mode, is primarily used during
Motorola’s internal production testing; however, it is accessible for
programming the CONFIG register, programming calibration data into
EEPROM, and supporting emulation and debugging during
development.
Technical Data
MC68HC11P2 — Rev 1.0
Operating Modes and On-Chip Memory
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