Motorola MC68030 User Manual page 29

Introduction
Registers D0–D7 are used as data registers for bit and bit field (1 to 32 bits), byte (8 bit),
word (16 bit), long-word (32 bit), and quad-word (64 bit) operations. Registers A0–A6 and
the user, interrupt, and master stack pointers are address registers that may be used as
software stack pointers or base address registers. Register A7 (shown as A7' and A7'' in
Figure 1-3) is a register designation that applies to the user stack pointer in the user privilege
level and to either the interrupt or master stack pointer in the supervisor privilege level. In
the supervisor privilege level, the active stack pointer (interrupt or master) is called the
supervisor stack pointer (SSP). In addition, the address registers may be used for word and
long-word operations. All of the 16 general-purpose registers (D0–D7, A0–A7) may be used
as index registers.
31
31
31
31
1-6
16 15
16 15
16 15
15
Figure 1-2. User Programming Model
MC68030 USER'S MANUAL
8 7 0
D0
D1
D2
D3
D4
D5
D6
D7
0
A0
A1
A2
A3
A4
A5
A6
0
A7 (USP)
0
PC
7
0
CCR
DATA
REGISTERS
ADDRESS
REGISTERS
USER STACK
POINTER
PROGRAM
COUNTER
CONDITION
CODE
REGISTER
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