Data Types And Addressing Modes; Instruction Set Overview - Motorola MC68030 User Manual

The MMU status register (MMUSR) contains memory management status information
resulting from a search of the address translation cache or the translation tree for a particular
logical address.

1.4 DATA TYPES AND ADDRESSING MODES

Seven basic data types are supported:
1. Bits
2. Bit Fields (Fields of consecutive bits, 1–32 bits long)
3. BCD Digits (Packed: 2 digits/byte, Unpacked: 1 digit/byte)
4. Byte Integers (8 bits)
5. Word Integers (16 bits)
6. Long-Word Integers (32 bits)
7. Quad-Word Integers (64 bits)
In addition, the instruction set supports operations on other data types such as memory
addresses. The coprocessor mechanism allows direct support of floating-point operations
with the MC68881 and MC68882 floating-point coprocessors as well as specialized user-
defined data types and functions.
The 18 addressing modes, shown in Table 1-1, include nine basic types:
1. Register Direct
2. Register Indirect
3. Register Indirect with Index
4. Memory Indirect
5. Program Counter Indirect with Displacement
6. Program Counter Indirect with Index
7. Program Counter Memory Indirect
8. Absolute
9. Immediate
The register indirect addressing modes can also postincrement, predecrement, offset, and
index addresses. The program counter relative mode also has index and offset capabilities.
As in the MC68020, both modes are extended to provide indirect reference through memory.
In addition to these addressing modes, many instructions implicitly specify the use of the
condition code register, stack pointer, and/or program counter.

1.5 INSTRUCTION SET OVERVIEW

The instructions in the MC68030 instruction set are listed in Table 1-2. The instruction set
has been tailored to support structured high-level languages and sophisticated operating
systems. Many instructions operate on bytes, words, or long words, and most instructions
can use any of the 18 addressing modes.
MOTOROLA MC68030 USER'S MANUAL
Introduction
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