MC68HC11KW1 Datasheet, PDF (47/238 Pages) Motorola, Inc – High-density complementary metal oxide semiconductor HCMOS) microcontroller unit

4.2
On-chip memory
The MC68HC11KW1 MCU includes 768 bytes of on-chip RAM and 640 bytes of EEPROM. The
bootloader ROM occupies a 448 byte block of the memory map. The CONFIG register is
implemented as a separate EEPROM byte.
Start
address
$0000
$00A0
$03A0
$0D80
$1000
Register
block
RAM
768 bytes
$x000
$x09F
$x0A0
$x39F





Each of these blocks
can be mapped to any
4K page boundary,
using the INIT register.
4
EEPROM ^$xD80 This block may be remapped
640 bytes _$xFFF to any 4K page, using INIT2.
$BE40
$C000
BootROM ^$BE40 Special bootstrap mode only.
Vectors _$BFFF Special modes only.
$FFC0
—$FFFF
Single
chip
Expanded
Special
bootstrap
Special
test
Vectors
$FFC0
$FFFF
Normal mode vectors.
Figure 4-1 MC68HC11KW1 memory map
4.2.1 Mapping allocations
Memory locations for on-chip resources are the same for both expanded and single chip modes.
The 160-byte register block originates at $0000 on reset and can be placed at any other 4K
boundary ($x000) after reset by writing an appropriate value to the INIT register. Refer to
Figure 4-1, which shows the memory map.
The on-board 768 byte block of RAM is initially located at $00A0 after reset. The RAM is divided
into two sections of 160 bytes and 608 bytes. If RAM and registers are both mapped to the same
4K boundary, RAM starts at $x0A0 and 160 bytes are remapped at $x300–$x39F. Otherwise,
RAM starts at $x000. See Figure 4-2.
Remapping is accomplished by writing appropriate values into the two nibbles of the INIT register.
See Section 4.3.2.2.
The 640-byte EEPROM is initially located at $0D80 after reset, when EEPROM is enabled in the
memory map by the CONFIG register. EEPROM can be placed in any other 4K page ($xD80) by
writing to the INIT2 register.
MC68HC11KW1
OPERATING MODES AND ON-CHIP MEMORY
4-3