DIO24, User Manual
D0
Memory Space Indicator
A ‘0’ indicates register maps into Memory space.
D2:1
Location of register (if memory space). Location values:
00 - Locate anywhere in 32-bit memory address space
D3 Prefetchable
A ‘0’ indicates reads are not prefetchable.
D31:4 Specifies which PCI address bits will be used to decode a PCI access to Local Address Space 0.
A ‘1’ indicates bit is included in address decode.
Local Address Space 0 value 0xFFFFF000 maps a 4kbyte range.
Since entire Local Address Space can be mapped into 4kb range, the remap register is not used.
5.2.2.
Mode/Arbitration Register
(PCI 0x08)
D7:0
Local bus Latency Timer (Unused)
D8:15 Local bus Pause Timer (Unused)
D16
Local bus Latency Timer Enable (Unused)
D17
Local bus Pause Timer Enable (Unused)
D18
Local bus BREQ Enable (Unused)
D20:19 DMA Channel Priority
00 = Rotational priority
01 = Channel 2 priority
10 = Channel 1 priority
11 = Reserved
D21
Local bus direct slave give up bus mode
A value of 1 indicates local bus will be released when PCI9080 write FIFO empty or read FIFO
full.
D22
Direct slave LLOCKo# Enable (Unused)
D23 PCI
Request
Mode
D24
PCI Rev 2.1 Mode
D25
PCI Read No Write Mode
D26
PCI Read with Write Flush Mode
D27
Gate the Local Bus Latency Timer with BREQ (Unused)
D28
PCI Read No Flush Mode
D29
Reads Device/Vendor ID or SubDevice/SubVendor ID
D31:30 Reserved
5.2.3.
Big/Little Endian Descriptor Register
(PCI 0x0C)
Since local bus is little endian, all bits should be left zero
5.2.4.
Local Address Space 0/Expansion ROM Bus Region Descriptor Register
(PCI 0x18, Reset 0x40030143)
D1:0
Memory Space 0 Local Bus Width
11 indicates 32-bit local bus
D5:2
Memory Space 0 Internal Wait States
A ‘0’ indicates no wait states required
D6
Memory Space 0 Ready Input Enable
A ‘1’ indicates Local Ready input enabled.
D7
Memory Space 0 Bterm Input Enable (Unused)
25
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