Hi, there is a friend that needs a special circuit to attach
to a PIC, but I can't find a single chip solution for him.

He needs a 2^8 bits counter, 8 stages, easy solution,
but it needs to have a serial output, not parallel, so
he could read the actual counter 8 bits using a 2 wire
serial transfer.

He can not use a microcontroller to count it because the
signal high frequency involved, around 15MHz.

In real this chip could be so dump and silly, with just
8 jk flipflops, a 8 bits shift register, and a couple
of gates, it could be built with only 6 pins:
Ground, Vcc, Pulses In, Reset, SDA + SCLK (2 wire comm).
A 7th pin could control counting in BCD or Binary, and
just to be snob, the 8th pin would be a bold "NC", or
then, used to signal zero count (carry bit).

A solution like that could use 8, 12, 16, 24 flipflops,
so a high speed counting could be easily read by a PIC
simply issuing RESET up/down, wait time for counting,
reset up to hold count and enable serial transfer,
and them issuing SCLKs to receive SDA data bits, then
reset down to clear counter and repeat again.

Does anybody knows anything like that available?  It is
incredible that I can't find anything so silly like that.

--------------------------------------------------------
Wagner Lipnharski - UST Research Inc. - Orlando, Florida
Forum and microcontroller web site:   http:/www.ustr.net
Microcontrollers Survey:  http://www.ustr.net/tellme.htm