PCI-SIO4 User Manual
General Standards Corporation
8302A Whitesburg Drive Huntsville, AL 35802, Phone: (256) 880-8787
45
3.2.2
M
ODE
/A
RBITRATION
R
EGISTER
:
(PCI
0
X
08)
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
3.2.3
B
IG
/L
ITTLE
E
NDIAN
D
ESCRIPTOR
R
EGISTER
:
(PCI
0
X
0C)
Since local bus is little endian, all bits should be left zero.
3.2.4
L
OCAL
A
DDRESS
S
PACE
0/E
XPANSION
ROM
B
US
R
EGION
D
ESCRIPTOR
R
EGISTER
(PCI
0
X
18,
R
ESET
0
X
40030143)
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)
D8
Memory Space 0 Prefetch Disable (Unused)
D9
Expansion ROM Space Prefetch Disable (Unused)
D10
Read Prefetch Count Enable (Unused)
D14:11
Prefetch Counter (Unused)
D15
Reserved
D17:16
Expansion ROM Space Local Bus Width (Unused)
D21:18
Expansion ROM Space Internal Wait States (Unused)
D22
Expansion ROM Space Ready Input Enable (Unused)
D23
Expansion ROM Space Bterm Input Enable (Unused)
D24
Memory Space 0 Burst Enable
D25
Extra Long Load from Serial Enable
D26
Expansion ROM Space Burst Enable (Unused)