At 09:13 4/19/00 +0100, you wrote: > >Also, I'm looking for suggestions on a data latch chip. I know > >how to construct a data latch out of discrete logic, but i need a whole > >chip for each line I want latched. 8 lines = 8 chips, and if I want 3 > >different latch channels I end up with 24 chips just for latch! Is there > >an 8 bit data latch on a chip? I just want something that has 8 input > >pins, 8 output pins, and an enable pin. (I suppose power connection pins > >too :)) Also I'd want to multiplex two or three of these on one 8 bit > >i/o port. Is this even possible? > >The obvious choice would be 74HC273. This chip is a little awkward in that the >input pin to a latch is immediately adjacent to the output pin. An alternative >is (I think) 74HC573. If I have the number correct, this is a similar chip >with >all the input pins on one side, and the output pins on the other side. I've used the 74HC589 a few times - sometimes 4 cascaded to get 32 bits. These are 8 parallel bits in & 1 serial bit out - an 8 bit shift register. You only need 4 i/o lines to shift the data in regardless of the # of chips. The timing is easy enough - give me a yell if you need some code for it. Regards...