Lpc2000

Charles,

>   I have a LPC2106 design that turns out to need more input lines then
> the 2106 has. Has any one have any luck with extending the I/O of the
> 2106 with the SPI bus?

yes, a 74HC595 (serial in, parallel/serial out shift register) as an 8 bit
output expander is used to control a 7-segment LED at the Embedded Artists
prototype board:
http://www.embeddedartists.com/products/boards/prototype.php, schematics
can be found from that page.

Knowing the 74Hc series a counterpart (parallel in - serial out) in the
same range. Looks like the 74HC597 is a cheap SPI input variant.
(http://www.standardics.philips.com/products/hc/pdf/74hc597.pdf)

Rob