User's Manual

Board Manual 61
Intel
®
IQ80321 I/O Processor Evaluation Platform
Hardware Reference Section
3.10.9.8 Switch S8E1- 5
When this input is pulled high (off), the bridge changes the output impedance of the drivers to the
opposite state than was assumed by default, as shown in Table 54 below:
3.10.9.9 Switch S8E1- 6
When this input is pulled high (off), the bridge changes the output impedance of the drivers to the
opposite state than was assumed by default, as shown in Table 57 below:
3.10.9.8.1 Switch S8E1 - 5: Descriptions
Switch Association Description Factory Default
S8E1-5 PCI-X Bridge
S_DRVR_MODE: Driver impedance selection for
SPCI-X bus.
On
Table 53. Switch S8E1 - 5: Settings and Operation Mode
S8E1-5 Operation Mode
Off
PCI 66, PCI-X 66/100: 40 Ω impedance.
PCI-X 133: 20 Ω impedance.
On
PCI 66, PCI-X 66/100: 20 Ω impedance.
PCI-X 133: 40 Ω impedance.
Table 54. Switch S8E1 - 5: Driver Mode Output Impedances
Secondary Bus Mode
Default Driver Mode
(S_DRVR_MODE=0, On)
Driver Mode when
(S_DRVR_MODE=1, Off)
Conventional PCI Multi-point (20 Ω) Point-to-point (40 Ω)
PCI-X 66 Multi-point (20 Ω) Point-to-point (40 Ω)
PCI-X 100 Multi-point (20 Ω) Point-to-point (40 Ω)
PCI-X 133 Point-to-point (40 Ω) Multi-point (20 Ω)
Table 55. Switch S8E1 - 6: Descriptions
Switch Association Description Factory Default
S8E1-6 PCI-X Bridge
P_DRVR_MODE: Driver impedance selection for
PPCI-X bus.
Off
Table 56. Switch S8E1 - 6: Settings and Operation Mode
S8E1-6 Operation Mode
Off
PCI 66, PCI-X 66/100: 20 Ω impedance.
PCI-X 133: 40 Ω impedance.
On
PCI 66, PCI-X 66/100: 40 Ω impedance.
PCI-X 133: 20 Ω impedance.
Table 57. Switch S8E1 - 6: Driver Mode Output Impedances
Primary Bus Mode
Default Driver Mode
(P_DRVR_MODE=0, On)
Driver Mode when
(P_DRVR_MODE=1, Off)
Conventional PCI Multi-point (20 Ω) Point-to-point (40 Ω)
PCI-X 66 Multi-point (20 Ω) Point-to-point (40 Ω)
PCI-X 100 Multi-point (20 Ω) Point-to-point (40 Ω)
PCI-X 133 Point-to-point (40 Ω) Multi-point (20 Ω)