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Dma scripts pointer (dsp), Registers: 0x2c–0x2f – Avago Technologies LSI53C1010R User Manual

Page 180

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4-62

Registers

Version 2.2

Copyright © 2000–2003 by LSI Logic Corporation. All rights reserved.

Registers: 0x2C–0x2F

DMA SCRIPTS Pointer (DSP)
Read/Write

DSP

DMA SCRIPTS Pointer

[31:0]

To execute SCSI SCRIPTS, the address of the first
SCRIPTS instruction must be written to this register. In
normal SCRIPTS operation, when the starting address of
the SCRIPT is written to this register, SCRIPTS are
automatically fetched and executed until an interrupt
condition occurs.

In the single-step mode, there is a single step interrupt
after each instruction is executed. The

DMA SCRIPTS Pointer (DSP)

register does not need to

be written with the next address. However, to fetch and
execute the next SCRIPTS command, the Start DMA bit
(bit 2,

DMA Control (DCNTL)

register) must be set each

time the step interrupt occurs. When writing this register
eight bits at a time, writing the upper eight bits begins
execution of SCSI SCRIPTS. The default value of this
register is zero.

Registers: 0x30–0x33

DMA SCRIPTS Pointer Save (DSPS)
Read/Write

DSPS

DMA SCRIPTS Pointer Save

[31:0]

This register contains the second Dword of a SCRIPTS
instruction. It is overwritten each time a SCRIPTS
instruction is fetched. When a SCRIPTS interrupt
instruction is executed, this register holds the interrupt
vector. The power-up value of this register is indeterminate.

31

0

DSP

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

31

0

DSPS

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0