mc68hc05l25 Freescale Semiconductor, Inc, mc68hc05l25 Datasheet - Page 35

• Manufacturer Part Number: mc68hc05l25
• Description: M68hc05 Microcontrollers Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

Chapter 4
Central Processor Unit (CPU) Core
4.1 Introduction
The MC68HC05L25 has an 8-K memory map. Therefore, it uses 13 bits of the address bus.
4.2 Registers
The MCU contains five registers which are hard-wired within the CPU and are not part of the memory
map. These five registers are shown in
4.2.1 Accumulator
The accumulator is a general-purpose 8-bit register as shown in
accumulator to hold operands and results of arithmetic calculations or non-arithmetic operations. The
accumulator is unaffected by a reset of the device.
Freescale Semiconductor
15
0
0
14
0
0
13
CONDITION CODE REGISTER
0
0
12
0
Figure 4-1. M68HC05 Programming Model
11
0
HALF-CARRY BIT (FROM BIT 3)
10
0
MC68HC05L25 Data Sheet, Rev. 3.1
Figure
PROGRAM COUNTER
9
0
8
0
INTERRUPT MASK
4-1.
NEGATIVE BIT
7
1
1
CARRY BIT
ZERO BIT
6
1
1
5
1
INDEX REGISTER
ACCUMULATOR
H
4
Figure
STACK POINTER
3
I
4-1. The CPU uses the
N
2
1
Z
C
0
CC
SP
PC
A
X
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