LSI LSI53C896, Technical Manual

Page: 179 / 370

SCSI Registers 4-67
normal SCRIPTS operation, once the starting address of
the SCRIPTS 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, but the Start DMA bit (bit 2, DMA Con-
trol (DCNTL) 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.
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
DSPS
x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x
*