Texas Instruments PCI445X manual Requirement of Pullup/Pulldown Resistors

System Implementation

Figure 1±6. Distributed DMA Signal Connection

PCREQ

PCI445X

PCGNT

South

Bridge

(ex., PIIX4)

1.3.5Requirement of Pullup/Pulldown Resistors

Note:

The PCI445X device has integrated pullup resistors and does not require external pullups.

Table 1±2. PC Card Interface Pullup Resistor List² ³

Terminal Name		Terminal Name		Terminal Name
(16-bit Memory PC Card)		(16-bit I/O PC Card)		(CardBus PC Card)	Pull Up to Voltage
					VCC
CD1			CD1	CCD1
					VCC
CD2			CD2	CCD2
					VCC
VS1			VS1	CVS1
					VCC
VS2			VS2	CVS2
A19		A19			VCCA or VCCB
				CBLOCK
A20		A20			VCCA or VCCB
				CSTOP
A21		A21			VCCA or VCCB
				CDEVSEL
A22		A22			VCCA or VCCB
				CTRDY
RESET		RESET			VCCA or VCCB
				CRST
					VCCA or VCCB
	WAIT		WAIT	CSERR
RFU					VCCA or VCCB
		INPACK		CREQ
BVD2				CAUDIO	VCCA or VCCB
		SPKR
BVD1				CSTSCHG	VCCA or VCCB
		STSCHG
A14		A14			VCCA or VCCB
				CPERR
READY					VCCA or VCCB
			IREQ	CINT
A15		A15			VCCA or VCCB
				CIRDY
WP					VCCA or VCCB
			IOIS16	CCLKRUN

²The PCI445X device has integrated pullup resistors and does not require external pullups. ³ CFRAME needs a pullup resistor, but it should be implemented on each PC Card.

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