摘要 |
A PC Card is provided which can be inserted in the PCMCIA slot of a host system either right side up or inverted. The card includes a front portion conforming to the PCMCIA Type II thickness standard and a rear portion conforming to the PCMCIA Type III thickness standard. The card is so configured that two cards can be stacked in complementary fashion and inserted in a host system Type III slot, one card thus being connected to one of the 68-pin slot connectors and the other card being connected to the other 68-pin slot connector. Circuitry is provided for use in an invertible PC Card for electronically detecting the presence, type and orientation of the card, for managing power supply voltages and for directing, or, if the card is inverted, for redirecting the signals appearing at the various pins of the card connector as necessary. Such circuitry comprises an application specific integrated circuit (ASIC) incorporating, besides the card function circuits, an orientation detection state machine and a signal mutliplexer.
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