Texas Instruments PCI445X PC Card Interface, 1.2.4 2-Wire I2C Interface for EEPROM, Revision

Models: PCI445X

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1.2.3PC Card Interface

System Implementation

1.2.3PC Card Interface

The PC Card interface has two modes: the 16-bit interface mode and the CardBus 32-bit interface mode.

￿Damping resistor on CCLK terminal

A series-damping resistor is recommended on the CCLK signal. The damping resistor is system dependent. If line impedance is in the 60±90-Ωrange, a 47-Ωresistor is recommended (see PC Card Standard,

Revision 7).

￿CD line filtering

PCI445X device has the advanced CDx line filtering circuit. It provides 90 s of noise immunity. A 270-pF filtering capacitor is still recommended for each of the power supply terminals: VCC, VCCS, and VCCP.

￿Socket power supply

Socket power is supplied through TPS22X6 power switches. The

PCI445X device requires VCCA and VCCB for the protection of the other device(s) on the bus.

1.2.42-Wire (I2C) Interface for EEPROM

The PCI445X device can load configuration registers from EEPROM after G_RST assertion. The SDA and SCL lines require pullup resistors to enable this function. Depending on the EEPROM requirements, the SDA and SCL lines must be pulled up to 3.3 V or 5 V.

Figure 1±3. EEPROM 2-Wire Interface

EEPROM

SDA

SCL

PCI445X ￿Damping resistor on CCLK terminal

TPS22X6

EEPROM slave address should be 101 0000b.

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Texas Instruments PCI445X PC Card Interface, 1.2.4 2-Wire I2C Interface for EEPROM, ±3. EEPROM 2-Wire Interface, Revision