MC68HC705C9A_1 Datasheet, PDF (33/157 Pages) Freescale Semiconductor, Inc – General Release Specification

Freescale Semiconductor, Inc.
General Release Specification — MC68HC705C9A
Section 2. Memory
2.1 Contents
2.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33
2.3 RAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34
2.4 EPROM. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37
2.5 EPROM Security. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37
2.6 ROM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37
2.7 I/O Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37
2.2 Introduction
The MCU has a 16-Kbyte memory map when configured as either an
MC68HC05C9A or an MC68HC05C12A. The memory map consists of
registers (I/O, control and status), user RAM, user EPROM, bootloader
ROM, and reset and interrupt vectors as shown in Figure 2-1 and
Figure 2-2.
When configured as an MC68HC05C9A, two control bits in the option
register ($3FDF) allow the user to switch between RAM and EPROM at
any time in two special areas of the memory map, $0020-$004F (48
bytes) and $0100-$017F (128 bytes). When configured as an
MC68HC05C12A, the section of the memory map from $0020 to $004F
is fixed as EPROM and the section from $0100 to $0FFF becomes
unused.
MC68HC705C9A — Rev. 2.0
Memory
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