Motorola MCF5281, MCF5282 Additions to the Instruction Set Architecture, Local Memory Registers

Models: MCF5282 MCF5281

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Additions to the Instruction Set Architecture

 

Table 2-3. ColdFire CPU Registers (continued)

 

 

 

 

 

 

Name

 

CPU Space (Rc)

Written with

Register Name

 

 

MOVEC

 

 

 

 

 

 

 

 

 

 

 

 

D0-D7

 

0x(0,1)80-0x(0,1)87

No

Data registers 0-7 (0 = load, 1 = store)

 

 

 

 

 

 

 

A0-A7

 

0x(0,1)88-0x(0,1)8F

No

Address registers 0-7 (0 = load, 1 = store)

 

 

 

 

 

A7 is user stack pointer

 

 

 

 

 

 

 

 

 

Processor Miscellaneous Registers

 

 

 

 

 

 

 

OTHER_A7

 

0x800

No

Other stack pointer

 

 

 

 

 

 

 

VBR

 

0x801

Yes

Vector base register

 

 

 

 

 

 

 

MACSR

 

0x804

No

MAC status register

 

 

 

 

 

 

 

MASK

 

0x805

No

MAC address mask register

 

 

 

 

 

 

 

ACC0-ACC3

 

0x806, 0x809,

No

MAC accumulators 0-3

 

 

 

0x80A, 0x80B

 

 

 

 

 

 

 

 

 

ACCext01

 

0x807

No

MAC accumulator 0, 1 extension bytes

 

 

 

 

 

 

 

ACCext23

 

0x808

No

MAC accumulator 2, 3 extension bytes

 

 

 

 

 

 

 

SR

 

0x80E

No

Status register

 

 

 

 

 

 

 

PC

 

0x80F

Yes

Program counter

 

 

 

 

 

 

 

 

 

Local Memory Registers

 

 

 

 

 

 

 

FLASHBAR

 

0xC04

Yes

Flash base address register

 

 

 

 

 

 

 

RAMBAR

 

0xC05

Yes

SRAM base address register

 

 

 

 

 

 

 

2.4Additions to the Instruction Set Architecture

The original ColdFire instruction set architecture (ISA) was derived from the M68000-family opcodes based on extensive analysis of embedded application code. After the initial ColdFire compilers were created, developers identified ISA additions that would enhance both code density and overall performance. Additionally, as users implemented ColdFire-based designs into a wide range of embedded systems, they identified frequently used instruction sequences that could be improved by the creation of new instructions. This observation was especially prevalent in development environments that made use of substantial amounts of assembly language code.

Table 2-4summarizes the new instructions added to Revision A+ ISA. For more details see Section 2.14, “ColdFire Instruction Set Architecture Enhancements.”

MOTOROLA

Chapter 2. ColdFire Core

2-9

Page 81
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Motorola MCF5281, MCF5282 Additions to the Instruction Set Architecture, Name CPU Space Rc Written with Register Name