Intel 41210 PCI Pullup Resistors Not Required, PCI-X Signals, PCI/PCI-X Frequency/Mode Straps

PCI-X Layout Guidelines

Table 6. PCI-X Signals

	A PCI Bus Segment:
	A_ACK64#, A_AD[63:0], A_CBE_[7:0]#, A_DEVSEL#, A_FRAME#,
	A_GNT_[5:0]#, A_IRDY#, A_LOCK#, A_PAR64, A_REQ64#, A_REQ_[5:0]#,
Timing Critical Signals	A_STOP#, A_TRDY#, A_CLKO[6:0], A_CLKI
	B PCI Bus Segment:
	B_ACK64#, B_AD[63:0], B_CBE_[7:0]#, B_DEVSEL#, B_FRAME#,
	B_GNT_[5:0]#, B_IRDY#, B_LOCK#, B_PAR64, B_REQ64#, B_REQ_[5:0]#,
	B_STOP#,B_TRDY#, B_CLKO[6:0], B_CLKI
	A PCI Bus Segment:
Reset Signals	A_RST#, A_PME#
	B PCI Bus Segment:
	B_RST#, B_PME#
	A PCI Bus Segment:
Non Timing Critical	A_133EN, A_IRQ[15:0]#, A_M66EN, A_PCIXCAP, A_PERR#, A_SERR#
Signals	B PCI Bus Segment:
	B_133EN, B_IRQ[15:0]#, B_M66EN, B_PCIXCAP, B_PERR#, B_SERR#

Table 7. PCI/PCI-X Frequency/Mode Straps

A_PCIXCAP, B_PCIXCAP	A_M66EN,	A_133EN,	Bus
	B_M66EN	B_133EN	Mode/
		(on board)	Freq
0	0	X	PCI 33
0	1	X	PCI 66
PCI-X 66MHz cards connect this
signal to ground through a 10KΩ	X	X	PCI-X 66
±5% resistor in parallel with a
0.01uF ±10% capacitor.
PCI-X 133 MHz cards connect			PCI-X 100
PCIXCAP to ground through a	X	0
0.01uF ±10% capacitor.
PCI-X 133 MHz cards connect			PCI-X 133
PCIXCAP to ground through a	X	1
0.01uF ±10% capacitor.

Note: All signals sampled on the rising edge of PERST#.

8.3.1PCI Pullup Resistors Not Required

PCI control signals on the 41210 Bridge do NOT require pullup resistors on the adapter card to ensure that they contain stable values when no agent is actively driving the bus. These include:

A_ACK64#, A_AD[63:32], A_CBE#[7:4], A_DEVSEL#, A_FRAME#, A_INTA#, A_INTB#, A_INTC#, A_INTD#, A_IRDY#, A_PERR#, A_PAR, A_GNT#[5:0], A_REQ#[5:0], A_LOCK#, A_PAR64, A_REQ64#, A_SERR#, A_STOP#, A_TRDY#, B_ACK64#, B_AD[63:32],

34 Intel® 41210 Serial to Parallel PCI Bridge Design Guide