PCI930

3-TO-1 ZOOMED VIDEO SWITCH

SCPS018B – OCTOBER 1997 – REVISED DECEMBER 1997

6

POST OFFICE BOX 655303

Table 3. ZV Switch Control and Status Terminals

TERMINAL

TYPE

FUNCTION

NAME

NO.

TYPE

FUNCTION

RESET

116

I

Chip reset. When asserted (driven low), the chip three-states all outputs. In addition, the PCI930

checks for a pullup resistor on the A/B STAT pin as denoted under ZV_xx terminal function.

A/B_STAT

48

I

PC Card ZV (Socket 0 or 1) active. This input indicates that either the A or B source from the PC Card

controller is active. This signal is used with A/B_SEL to determine which socket ZV source drives the

ZV_xx outputs. The A or B source can be passed to ZV_xx if the C source is either of lower precedence,

or is not sourcing valid ZV data, as indicated by the C_STAT signal.

A/B_SEL

49

I

Socket A/B select. When this pin and A/B_STAT are high, the PC Card socket A ZV data is valid. When

this pin is low, and the A/B_STAT input is high, the PC Card socket B ZV data is valid. This input has

no meaning if the A/B_STAT input is low.

C_STAT

50

I

C source status. When this input is high, the ZV source from interface C is valid, and can be driven

to the ZV_xx outputs. The C source can be passed to ZV_xx if the A and B sources are either of lower

precedence, or A or B is not sourcing valid ZV data.

ZV_OE

114

I

ZV output I/F enable. When this terminal is low, the ZV switch drives the ZV_xx terminals.

ZV_STAT

113

O

ZV output status. This terminal is driven high when the ZV switch drives the ZV_xx terminals.

ZV_xx State

N/A

N/A

When a pullup resistor is present on the A/B_STAT pin during RESET, then the ZV_xx interface is

three-stated if the ZV_xx interface is inactive. During the default state, no pullup resistor, a reset drives

the ZV_xx interface to a logic low state when inactive.