On Wed, Mar 17, 2004 at 02:54:27PM -0500, D. Jay Newman wrote:
> Hi:
>
> I have a problem where I would like to interface four chips with an
> spi-like interface. These chips have no chip-select line.
>
> Is there some sort of mutiplexer chip that I can use to choose which
> slave chip I want to send the data/clock signals to?

Actually you only have to multiplex the clock. Data doesn't mean anything
without a clock.

A 74HC138 or 74HC139 decoder will do the job. Tie the clock to the E pin
and use the two/three select pins to pick the output. The output will follow
the E pin for the selected output and all other outputs are high.

BAJ

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