Dma scripts pointer (dsp), Scripts pointer (dsp), Dma scripts – LSI 53C875A User Manual
Page 156: Pointer (dsp), Next address (dnad), Dma next address (dnad), Registers: 0x2c–0x2f
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Registers
Registers: 0x28–0x2B
DMA Next Address (DNAD)
Read/Write
DNAD
DMA Next Address
[31:0]
This 32-bit register contains the general purpose address
pointer. At the start of some SCRIPTS operations, its
value is copied from the
register. Its value may not be valid except in
certain abort conditions. The default value of this register
is zero.
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, once the starting address of
the SCRIPT is written to this register, SCRIPTS are
automatically fetched and executed until an interrupt
condition occurs.
In single step mode, there is a single step interrupt after
each instruction is executed. The
register does not need to be written with the next
address, but the Start DMA bit (bit 2,
register) must be set each time the step
interrupt occurs to fetch and execute the next SCRIPTS
command. 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.
See
Section 5.4.2, “Second Dword,”
for register detail.
31
0
DNAD
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
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