MC68HC05X16 Datasheet, PDF (43/232 Pages) Freescale Semiconductor, Inc – High-density complementary metal oxide semiconductor HCMOS) microcontroller unit

Freescale Semiconductor, Inc.
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MEMORY AND REGISTERS
The MC68HC05X16 MCU is capable of addressing 16384 bytes of memory and registers with its
program counter. The memory map includes 15118 bytes of user ROM (including user vectors),
576 bytes of bootstrap ROM, 352 bytes of RAM and 256 bytes of EEPROM.
3.1
Registers
All the I/O, control and status registers of the MC68HC05X16 are contained within the first 32-byte
block of the memory map, as shown in Figure 3-1. MCAN registers are contained in the next 30
bytes of memory.
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. The user RAM also
comprises 176 bytes from $0250 to $02FF which is completely free for the user.
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 15118 bytes of ROM mapped as follows:
• 15102 bytes of user ROM from $0300 to $3DFD
• 16 bytes of user vectors from $3FF0 to $3FFF
MC68HC05X16
MEMORY AND REGISTERS
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