Mike Chambers
Veteran Member
- Joined
- Sep 2, 2006
- Messages
- 2,621
the 6502 needs a clean square wave to drive it, and i was wondering if the 8284A can put out a suitable signal for it. i believe the 6502 needs a 50% duty cycle, but does this actually matter? there seem to be three outputs from the 8284A that give some sort of clock signal.
if i put a 1 MHz xtal on X1 and X2 (and tie a few lines as necessary) does the 8284A turn it into a proper square wave? and do i have these outputs correct:
1 MHz into X1/X2:
OSC = 1 MHz 50% duty square wave
CLK = 1 MHz 1/3 duty square wave
PCLK = 1 MHz 1/6 duty square wave
i know OSC is meant to drive other 8284A chips, so does it actually send out a clean square on that pin or is it a direct connection to the xtal? either i am bad at reading, or the datasheet isn't clear on much of this. i am willing to entertain both possibilities.
if i'm wrong, and the 8284A won't do the job for a 6502, what is the simplest circuit i can build to make a good driving signal? so many of you guys are great with EE-type stuff. thanks!
if i put a 1 MHz xtal on X1 and X2 (and tie a few lines as necessary) does the 8284A turn it into a proper square wave? and do i have these outputs correct:
1 MHz into X1/X2:
OSC = 1 MHz 50% duty square wave
CLK = 1 MHz 1/3 duty square wave
PCLK = 1 MHz 1/6 duty square wave
i know OSC is meant to drive other 8284A chips, so does it actually send out a clean square on that pin or is it a direct connection to the xtal? either i am bad at reading, or the datasheet isn't clear on much of this. i am willing to entertain both possibilities.
if i'm wrong, and the 8284A won't do the job for a 6502, what is the simplest circuit i can build to make a good driving signal? so many of you guys are great with EE-type stuff. thanks!