MC68HC05SU3A Datasheet, PDF (47/80 Pages) Freescale Semiconductor, Inc – Fully static chip design featuring the industry standard 8-bit M68HC05 core

Freescale Semiconductor, Inc.
7
CPU CORE AND INSTRUCTION SET
This section provides a description of the CPU core registers, the instruction set and the
addressing modes of the MC68HC05SU3A.
7.1
Registers
The MCU contains five registers, as shown in the programming model of Figure 7-1. The interrupt
stacking order is shown in Figure 7-2.
7
7
0
7
0
15
7
0
15
7
0
0000000011
7
0
111H I NZC
Accumulator
Index register
Program counter
Stack pointer
Condition code register
Carry / borrow
Zero
Negative
Interrupt mask
Half carry
Figure 7-1 Programming model
7.1.1 Accumulator (A)
The accumulator is a general purpose 8-bit register used to hold operands and results of
arithmetic calculations or data manipulations.
MC68HC05SU3A
CPU CORE AND INSTRUCTION SET
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TPG
7-1