LSI 53C810A - Manual (Page 119)

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Register: 0x3A (0xBA)
Scratch Byte Register (SBR)
Read/Write
SBR Scratch Byte Register [7:0]
This is a general purpose register. Apart from CPU
access, only register Read/Write and Memory Moves into
this register alters its contents. The default value of this
register is zero. This register is called the DMA Watchdog
Timer on previous LSI53C8XX family products.
Register: 0x3B (0xBB)
DMA Control (DCNTL)
Read/Write
CLSE Cache Line Size Enable 7
Setting this bit enables the LSI53C810A to sense and
react to cache line boundaries set up by the
DMA Mode
(DMODE) or PCI Cache Line Size register, whichever
contains the smaller value. Clearing this bit disables the
cache line size logic and the LSI53C810A monitors the
cache line size using the
DMA Mode (DMODE) register.
PFF Prefetch Flush 6
Setting this bit will cause the prefetch unit to flush its
contents. The bit clears after the flush is complete.
PFEN Prefetch Enable 5
Setting this bit enables the prefetch unit if the burst size
is equal to or greater than four. For more information on
SCRIPTS instruction prefetching, see
Chapter 2, “Func-
tional Description.”
7 0
SBR
0 0 0 0 0 0 0 0
7 6 5 4 3 2 1 0
CLSE PFF PFEN SSM IRQM STD IRQD COM
0 0 0 0 0 0 0 0