I've had a hunt and can't find any component that matches my requirements, so maybe I'm not just searching for the correct name.

Essentially I'd like some sort of FIFO memory. It would have eight data lines for input and a control pin to clock in data. It would then have eight pins for output and a control pin to clock out data. Ideally the output port would also be tri-stated to make it easier to attach to a CPU's data bus, though this is not essential as the same effect could be achieved with an additional tri-state buffer or latch IC.

Finally, a pin that changes state to indicate whether the FIFO contains either zero or more than zero items would be useful.

The FIFO doesn't need to have much memory (though more than one data word would be useful, otherwise I could just use a latch!) It would be useful to interface other components (such as microcontrollers) to a microprocessor system where the microcontroller would not be fast enough to respond to conventional I/O read or write cycles; the microcontroller would clock data into the FIFO as and when it needs to, and the microprocessor checks the FIFO state and reads in data as required.
What's wrong with a bunch of mutually-clocked shift registers?

Edit: ok, that's not exactly what you're talking about, but certainly you could have a 2D array of mutually-clocked shift registers to have an arbibtrary-depth, arbitrary-width FIFO.
The size, chiefly. Wink I'm aiming for a single chip solution (doesn't need to store much - eight to sixteen bytes or so).

Edit: For a multiple-chip solution I'd probably go for a very small SRAM coupled with a pair of counter ICs to create a simple ring buffer.
benryves wrote:
The size, chiefly. Wink I'm aiming for a single chip solution (doesn't need to store much - eight to sixteen bytes or so).

Edit: For a multiple-chip solution I'd probably go for a very small SRAM coupled with a pair of counter ICs to create a simple ring buffer.
Hmm, does something like the 74HC40105N help at all? It's only 4 bits wide, but maybe something else in its family is wider?

http://www.datasheetcatalog.org/datasheet/philips/74HC40105N.pdf
A bit more digging turns up a plentiful supply of 1- and 4-bit FIFOs, then a sudden leap to 18-bit ones in SOIC packaging. The IDT7201LA12P looks good (9-bit), but it's out of stock in the places I usually source components from. I'll continue hunting, thanks for your advice!
benryves wrote:
A bit more digging turns up a plentiful supply of 1- and 4-bit FIFOs, then a sudden leap to 18-bit ones in SOIC packaging. The IDT7201LA12P looks good (9-bit), but it's out of stock in the places I usually source components from. I'll continue hunting, thanks for your advice!
Ah excellent, glad to hear it. I hope you'll post the part you finally find in case anyone else is looking for similar stuff. Smile
  
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