MC68HC05B4 Datasheet, PDF (43/298 Pages) Motorola, Inc – High-density Complementary Metal Oxide Semiconductor (HCMOS) Microcomputer Unit

3
3
MEMORY AND REGISTERS
The MC68HC05B6 MCU is capable of addressing 8192 bytes of memory and registers with its
program counter. The memory map includes 5950 bytes of User ROM (including User vectors),
432 bytes of self check ROM, 176 bytes of RAM and 256 bytes of EEPROM.
3.1
Registers
All the I/O, control and status registers of the MC68HC05B6 are contained within the first 32-byte
block of the memory map, as shown in Figure 3-1. The miscellaneous register is shown in
Section 3.8 as this register contains bits which are relevant to several modules.
3.2
RAM
The user RAM comprises 176 bytes of memory, from $0050 to $00FF. This is shared with a 64 byte
stack area. The stack begins at $00FF and may extend down to $00C0.
Note:
Using the stack area for data storage or temporary work locations requires care to prevent
the data from being overwritten due to stacking from an interrupt or subroutine call.
3.3
ROM
The User ROM consists of 5950 bytes of ROM mapped as follows:
• 48 bytes of page zero ROM from $0020 to $004F
• 5888 bytes of User ROM from $0800 to $1EFF
• 14 bytes of User vectors from $1FF2 to $1FFF
MC68HC05B6
Rev. 4
MEMORY AND REGISTERS
TPG
MOTOROLA
3-1