Figure6.2 block move instruction register, Block move instruction register – LSI 53C810A User Manual

Page 148

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6-8

Instruction Set of the I/O Processor

Figure 6.2

Block Move Instruction Register

Prior to the start of an I/O, the

Data Structure Address

(DSA)

register should be loaded with the base address of

the I/O data structure. The address may be any address
on a Dword boundary.

After a Table Indirect opcode is fetched, the DSA is
added to the 24-bit signed offset value from the opcode
to generate the address of the required data; both
positive and negative offsets are allowed. A subsequent
fetch from that address brings the data values into the
chip.

For a MOVE instruction, the 24-bit byte count is fetched
from system memory. Then the 32-bit physical address is
brought into the LSI53C810A. Execution of the move
begins at this point.

31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9

8

7

6

5

4

3

2

1

0

31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9

8

7

6

5

4

3

2

1

0

DSPS Register

DCMD Register

DBC Register

24-bit Block Move Byte Counter

I/O

C/D

MSG/

Opcode

Table Indirect Addressing

Indirect Addressing (LSI53C700 Family Compatible)

0 - Instruction Type - Block Move

0 - Instruction Type - Block Move

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