Coprocessors

5

The operation and configuration of the Intel® StrongARM® SA-1100 Microprocessor (SA-1100) is controlled with coprocessor instructions, configuration pins, and memory-management page tables. The coprocessor 15 instructions manipulate on-chip registers that control the configuration of the cache, write buffer, MMU, read buffer, breakpoints, and other configuration options.

Note: The gray areas in the register and translation diagrams are reserved and should be programmed 0 for future compatibility.

5.1Internal Coprocessor Instructions

The on-chip cache, MMU, write buffer, and read buffers are controlled using MRC instructions and MCR instructions. These operations to coprocessor 15 are allowed only in nonuser modes except when read-buffer operations are explicitly enabled. The undefined instruction trap is taken if accesses are attempted in user mode. Figure 5-1shows the format of internal coprocessor instructions MRC and MCR.

Figure 5-1. Format of Internal Coprocessor Instructions MRC and MCR

31

28

27

24

23

21

20

19

16

15

12

11

8

7

5

4

3

0

Cond

1

1 1

0 n

CRn

Rd

1

1 1

1

OPC_2 1

CRm

Cond

ARM™ condition codes

n

1

MRC register read

 

0

MCR register write

CRn

SA-1100 register

Rd

ARM register

OPC_2

Function bits for some MRC/MCR instructions

CRm

Function bits for some MRC/MCR instructions

SA-1100 Developer’s Manual

5-1

Page 45
Image 45
Intel SA-1100 manual Coprocessors, Internal Coprocessor Instructions