I'm not sure there's a ready way for a PC to talk to a device interfaced with an 805x in mode-0.

There's no telling why Munaza Yousuf wants to use this type of interface, but with enough hardware support for the counters, he can make it run pretty fast, or, if he clocks things with his 805x, he can go slow. If he wants to go REALLY slowly, then he can bit-bang. He didn't say what his intended data rate will be. He hasn't said which version of the 805x he's using. If it's a four-clocker, he can probably do things in Mode 0, if that meets his rate requirement. We'll have to wait until he tells us, though.

I've already gone on at some length about the 805x's weaknesses in synchronous communication via mode-0. The standard 12-clockers can't do it at all, since the data rate is oscillator/12 and that's the instruction rate as well. There isn't time to turn a loop in which one either responds to an interrupt or checks the status of the RI or TI bits, moves a byte in the appropriate direction, and clears the RI or TI bit when you have only eight instruction cycles. This renders the classic Mode-0 serial channel useless for syncrhonous communication.

Maybe that's not what the O/P wants to do, however. Nonetheless, if he tells us what his requirements are, and how this particular hardware scheme satisfies it, then I imagine a solution can be found forthwith.

RE