MC68332 Datasheet, PDF (46/88 Pages) Freescale Semiconductor, Inc – 32-Bit Modular Microcontroller

Freescale Semiconductor, Inc.
4.3 Status Register
The status register contains the condition codes that reflect the results of a previous operation and can
be used for conditional instruction execution in a program. The lower byte containing the condition
codes is the only portion of the register available at the user privilege level; it is referenced as the con-
dition code register (CCR) in user programs. At the supervisor privilege level, software can access the
full status register, including the interrupt priority mask and additional control bits.
SR —Status Register
15
14 13 12 11 10
8
7
6
5
4
3
2
1
0
T1
T0 S
0
0
IP
0
0
0
X
N
Z
V
C
RESET:
0
0
1
0
0
1
1
1
0
0
0
UUUUU
System Byte
T[1:0] —Trace Enable
S —Supervisor/User State
Bits [12:11] —Unimplemented
IP[2:0] —Interrupt Priority Mask
User Byte (Condition Code Register)
Bits [7:5] — Unimplemented
X — Extend
N — Negative
Z — Zero
V — Overflow
C — Carry
4.4 Data Types
Six basic data types are supported:
• Bits
• Packed Binary Coded Decimal Digits
• Byte Integers (8 bits)
• Word Integers (16 bits)
• Long-Word Integers (32 bits)
• Quad-Word Integers (64 bits)
4.5 Addressing Modes
Addressing in the CPU32 is register-oriented. Most instructions allow the results of the specified oper-
ation to be placed either in a register or directly in memory. This flexibility eliminates the need for extra
instructions to store register contents in memory. The CPU32 supports seven basic addressing modes:
• Register direct
• Register indirect
• Register indirect with index
• Program counter indirect with displacement
• Program counter indirect with index
• Absolute
• Immediate
Included in the register indirect addressing modes are the capabilities to post-increment, predecrement,
and offset. The program counter relative mode also has index and offset capabilities. In addition to
these addressing modes, many instructions implicitly specify the use of the status register, stack point-
er, or program counter.
MOTOROLA
46
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MC68332
MC68332TS/D