MC68HC812A4 Datasheet, PDF (87/342 Pages) Motorola, Inc – 16-bit device composed of standard on-chip peripheral modules connected by an intermodule bus. Modules include

Operating Modes and Resource Mapping
Mode and Resource Mapping Registers
EME — Emulate Port E Bit
In single-chip mode, PORTE and DDRE are always in the map
regardless of the state of this bit.
1 = If in an expanded mode, PORTE and DDRE are removed from
the internal memory map. Removing the registers from the
map allows the user to emulate the function of these registers
externally.
0 = PORTE and DDRE in the memory map
Normal modes: Write once
Special modes: Write anytime except the first time
5.5.2 Register Initialization Register
After reset, the 512-byte register block resides at location $0000 but can
be reassigned to any 2-Kbyte boundary within the standard 64-Kbyte
address space. Mapping of internal registers is controlled by five bits in
the INITRG register. The register block occupies the first 512 bytes of
the 2-Kbyte block.
Address: $0011
Bit 7
6
5
4
3
2
1
Bit 0
Read:
REG15 REG14 REG13 REG12 REG11
0
0
0
Write:
Reset: 0
0
0
0
0
0
0
0
Figure 5-2. Register Initialization Register (INITRG)
Read: Anytime
Write: Once in normal modes; anytime in special modes
REG15–REG11 — Register Position Bits
These bits specify the upper five bits of the 16-bit register address.
Advance Information
MOTOROLA
Operating Modes and Resource Mapping
MC68HC812A4 — Rev. 3.0
87