Intel Xeon - Secondary IDE Connector Requirements; Connection Requirements for Secondary IDE Connector

I/O Controller Hub
122 Design Guide
9.1.4 Secondary IDE Connector Requirements
The requirements for the secondary IDE connector are shown in Figure 9-3.
• 22 Ω – 47 Ω series resistors are required on RESET#. The correct value should be determined
for each unique motherboard design, based on signal quality.
• An 8.2 kΩ to 10 kΩ pull-up resistor is required on IRQ15 to VCC_3.3.
• A 4.7 kΩ ± 5% pull-up resistor to VCC_3.3 is required on SIORDY.
• Series resistors can be placed on the control and data lines to improve signal quality. The
resistors are placed as close to the connector as possible. Values are determined for each
unique motherboard design.
• The 10 kΩ resistor to ground on the PDIAG#/CBLID# signal is required on the Secondary
Connector. This change is to prevent the GPIOx pin from floating if a device is not present on
the IDE interface.
NOTE:
1
Because of ringing, PCIRST# must be buffered.
Figure 9-3. Connection Requirements for Secondary IDE Connector
CSEL
3.3 V
3.3 V
4.7 kΩ 8.2–10 kΩ
10 kΩ
SIORDY (SRDSTB/SWDMARDY#)
SDIAG# / CBLID#
IRQ15
GPIOx
Secondary IDE Connector
Intel
®
ICH3-S
PCIRST#
1
SDD[15:0]
SDA[2:0]
SDCS[3,1]#
SDIOR#
SDIOW#
SDDREQ
SDDACK#
22–47 Ω
IDERST#