Datasheet

3−4
3.5 PC Card Applications
This section describes the PC Card interfaces of the PCI1520.
• Card insertion/removal and recognition
• P
2
C power-switch interface
• Zoomed video support
• Speaker and audio applications
• LED socket activity indicators
• CardBus socket registers
3.5.1 PC Card Insertion/Removal and Recognition
The PC Card Standard (release 7.1) addresses the card-detection and recognition process through an interrogation
procedure that the socket must initiate on card insertion into a cold, nonpowered socket. Through this interrogation,
card voltage requirements and interface (16-bit versus CardBus) are determined.
The scheme uses the card-detect and voltage-sense signals. The configuration of these four terminals identifies the
card type and voltage requirements of the PC Card interface. The encoding scheme is defined in the PC Card
Standard (release 7.1) and in Table 3−1.
Table 3−1. PC Card Card-Detect and Voltage-Sense Connections
CD2//CCD2 CD1//CCD1 VS2//CVS2 VS1//CVS1 KEY INTERFACE VOLTAGE
Ground Ground Open Open 5 V 16-bit PC Card 5 V
Ground Ground Open Ground 5 V 16-bit PC Card 5 V and 3.3 V
Ground Ground Ground Ground 5 V 16-bit PC Card 5 V, 3.3 V, and X.X V
Ground Ground Open Ground LV 16-bit PC Card 3.3 V
Ground Connect to CVS1 Open Connect to CCD1 LV CardBus PC Card 3.3 V
Ground Ground Ground Ground LV 16-bit PC Card 3.3 V and X.X V
Connect to CVS2 Ground Connect to CCD2 Ground LV CardBus PC Card 3.3 V and X.X V
Connect to CVS1 Ground Ground Connect to CCD2 LV CardBus PC Card 3.3 V, X.X V, and Y.Y V
Ground Ground Ground Open LV 16-bit PC Card X.X V
Connect to CVS2 Ground Connect to CCD2 Open LV CardBus PC Card X.X V
Ground Connect to CVS2 Connect to CCD1 Open LV CardBus PC Card X.X V and Y.Y V
Connect to CVS1 Ground Open Connect to CCD2 LV CardBus PC Card Y.Y V
Ground Connect to CVS1 Ground Connect to CCD1 Reserved
Ground Connect to CVS2 Connect to CCD1 Ground Reserved
3.5.2 P
2
C Power-Switch Interface (TPS222X)
The PCI1520 provides a PCMCIA peripheral control (P
2
C) interface for control of the PC Card power switch. The
CLOCK, DATA, and LATCH terminals interface with the TI TPS222X dual-slot PC Card power interface switches to
provide power switch support. Figure 3−3 illustrates a typical application where the PCI1520 represents the PCMCIA
controller. Table 3−2 shows the available power switch options compatible with the PCI1520.