MC912D60AVPVE8 Datasheet, PDF (79/460 Pages) Freescale Semiconductor, Inc – HC12 Microcontrollers

Operating Modes and Resource Mapping
Internal Resource Mapping
MMSWAI — Memory Mapping Interface Stop in Wait Control
This bit controls access to the memory mapping interface when in
Wait mode.
Normal modes: write anytime; special modes: write never. Read
anytime.
0 = Memory mapping interface continues to function during Wait
mode.
1 = Memory mapping interface access is shut down during Wait
mode.
5.5.2 RAM Mapping
The MC68HC912D60A has 2K byte of fully static RAM that is used for
storing instructions, variables, and temporary data during program
execution. After reset, RAM addressing begins at location $0000 but can
be assigned to any 2K byte boundary within the standard 64K byte
address space. Mapping of internal RAM is controlled by five bits in the
INITRM register.
After reset, the first 512 bytes of RAM have their access inhibited by the
presence of the register address space. After initial MCU configuration,
it is recommended to map the register space at location $0800.
Bit 7
6
5
4
3
2
RAM15 RAM14 RAM13 RAM12 RAM11
0
RESET:
0
0
0
0
0
0
INITRM — Initialization of Internal RAM Position Register
1
Bit 0
0
0
0
0
$0010
RAM[15:11] — Internal RAM map position
These bits specify the upper five bits of the 16-bit RAM address.
Normal modes: write once; special modes: write anytime. Read
anytime.
MC68HC912D60A — Rev. 3.1
Freescale Semiconductor
Operating Modes and Resource Mapping
Technical Data
79