Terminations

Terminations4

This chapter details all the recommended Intel® 31154 133 MHz PCI Bridge terminations required for the different operating modes.

The chapter provides the recommended pull-up and pull-down terminations for a 31154 layout. Table 5 lists these 31154 termination values. Note that for motherboards, the PCI Local Bus Specification, Revision 2.3 requires that the PCI signals provide the termination resistors.

Table 5.

Pull-Up/Pull-Down Terminations (Sheet 1 of 9)

 

 

 

 

 

 

Signal

 

Pull-Up/Pull-Down or Termination (See Note 1)

 

Comments

 

 

 

 

 

PCI Reset

 

 

 

 

 

 

 

 

 

P_RST#

 

Connect to bus RST# signal on primary PCI bus.

 

 

 

 

 

 

 

S_RST#

 

Connect to bus RST# signal on secondary PCI

 

 

 

bus.

 

 

 

 

 

 

 

 

 

 

Primary PCI Signals

 

 

 

 

 

 

P_AD[31:0]

 

Connect to primary PCI bus AD[31:0].

 

 

 

 

 

 

 

 

 

For 64-bit primary PCI bus:

 

 

 

 

• Connect to the AD[63:32] bits of the primary

 

 

P_AD[63:32]

 

PCI bus.

 

 

 

For 32 bit Primary PCI Bus:

 

 

 

 

 

 

 

 

• Pull up through individual external resistors

 

 

 

 

(see Note 2 and Note 3).

 

 

 

 

 

 

 

P_CBE[3:0]

 

Connect to the CBE[3:0}# bits of the primary PCI

 

 

 

bus.

 

 

 

 

 

 

 

 

 

 

 

 

 

For 64-bit primary PCI bus:

 

 

 

 

• Connect to the CBE[7:4]# bits of the primary

 

 

P_CBE[7:4]#

 

PCI bus.

 

 

 

For 32-bit primary PCI Bus:

 

 

 

 

 

 

 

 

• Pull up through individual external resistors

 

 

 

 

(see Note 2 and Note 3).

 

 

 

 

 

 

 

P_FRAME#

 

Connect to FRAME# of the primary PCI bus.

 

 

 

 

 

 

 

P_DEVSEL#

 

Connect to DEVSEL# of the primary PCI bus.

 

 

 

 

 

 

 

P_IRDY#

 

Connect to IRDY# of the primary PCI bus.

 

 

 

 

 

 

 

P_TRDY#

 

Connect to TRDY# of the primary PCI bus.

 

 

 

 

 

 

 

P_STOP#

 

Connect to STOP# of the primary PCI bus.

 

 

 

 

 

 

 

NOTES:

1.The recommended value for pull-up resistors for PCI applications is 5.6 K(note that the minimum value for PCI 3.3 V signaling RMIN = 2.42 K, RTYP = 8.2 K, as per the PCI Local Bus Specification, Revision 2.3, section 4.3.3).

2.The recommended value for pull-up resistors for PCI-X applications is 8.2 K. For PCI-X, the minimum pull-up resistor value is 5 K, as per the PCI-X Addendum to the PCI Local Bus Specification, Revision 1.0b, section 9.7.

3.For plug-in card implementations, the pull-up must be on the motherboard.

4.Connect PVIO and SVIO pull-up resistors to 5 V or 3.3 V power supply through an external resistor—25 (5 V) or

0 (3.3 V), depending on the signaling level of the primary/secondary PCI bus. Refer to the power-sequencing guidelines in Section 8.2 on page 58.

Intel® 31154 133 MHz PCI Bridge Design Guide Design Guide

19

Page 19
Image 19
Intel 31154 manual Terminations4, Pull-Up/Pull-Down Terminations Sheet 1