Texas Instruments PCI445X manual 12.9 SMI, Socket Power Lock, 12.11VCC Protection

System Features Selection

CCLK can be slowed down rather than stopped by CCLKRUN. If CCLKRUN is set, the CLKCTRLEN (CardBus socket 20h, bit 16) and CLKCTR (CardBus socket 20h, bit 0) bits are both set to 1. The clock is slowed down to 1/16. In this mode the PCI clock is not allowed to stop.

1.1.12.9 SMI

A PC card power change event can be reported to the system as SMI (IRQ2 or CSC). It can be controlled with the SMIROUTE, SMISTATUS, and SMIENB bits (system control register, PCI offset 80h, bits 26, 25, and 24, respectively).

1.1.12.10 Socket Power Lock

Socket power can be protected from software control in the D3hot state. It can be done with the socket power lock bit (device control register, PCI offset 92h, bit 7).

1.1.12.11VCC Protection

The VCCPROT bit (system control register, PCI offset 80h, bit 21) controls VCC protection for 16-bit cards. This feature protects applying the wrong (higher) VCC to the 16-bit card. If a 3.3-V-only card is inserted, then it protects against applying 5 V to the card. Default is 0 (enabled).

1.1.12.12 ZV Port Control and Auto Detect Function

Internal zoomed video buffers can be controlled with the ZV autodetect function. It can be turned on by setting the zoomed video autodetect bit (multimedia control register, PCI offset 84h, bit 5) to 1. Autodetect priority encoding bits (multimedia control register, PCI offset 84h, bits 4±2) can control the priority scheme.

PCI445X Device 1-7