PCI1221 datasheet(26/123 Pages) TI

26 / 123 page

PCI1221 GHK/PDV

PC CARD CONTROLLERS

SCPS042 – JULY 1998

POST OFFICE BOX 655303

• DALLAS, TEXAS 75265

zoom video support

The PCI1221 allows for the implementation of zoom video for PC Cards. Zoom video is supported by setting

the ZVENABLE bit in the card control register on a per socket function basis. Setting this bit puts PC Card-16

address lines A25–A4 of the PC Card interface in the high-impedance state. These lines can then be used to

transfer video and audio data directly to the appropriate controller. Card address lines A3-A0 can still be used

to access PC Card CIS registers for PC Card configuration. Figure 4 illustrates a PCI1221 ZV implementation.

CRT

VGA

Controller

Audio

Codec

PCI1221

Zoom Video

Port

PCM

Audio

Input

PCI Bus

PC Card

Interface

Video

Audio

PC Card

Motherboard

Speakers

Figure 4. Zoom Video Implementation Using PCI1221

Not shown in Figure 4 is the multiplexing scheme used to route either socket 0 or socket 1 ZV source to the

graphics controller. The PCI1221 provides ZVSTAT, ZVSEL0, and ZVSEL1 signals on the multifunction

terminals to switch external bus drivers. Figure 5 shows an implementation for switching between three ZV

streams using external logic.

ZVSTAT

ZVSEL0

ZVSEL1

PCI1221

Figure 5. Zoom Video Switching Application

PCI1221 Datasheet(PDF) 26 Page - Texas Instruments