The Secret OSC instruction
James Newton
Posts: 329
I hope no one minds that I started this as a new thread, the regular one is getting quite long. This is a potentially valuable instruction I think, and I'd love to be able to document it a bit better.
Paul Baker refers to " the $044 (swap osc pin with w) " but Peter said it "shifts the oscillator pin into/outof W"
Does anyone know what direction it shifts or if it actually swaps a bit in/out of W?
Can it be used in any other situation than with an internal osc?
Doesn't the SXKey provide the clock when it is connected and so this must be using one of the osc pins while the key drives the other one right?
How does the direction get set? In or Out? Is one OSC pin always the In and the other the Out? If so, how does the SXKey continue to provide a clock while at the same time transmitting data?
Could it be that one OSC pin is an input while the other is high and and output when the other is low?
Ok, thats enough questions on this one.
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James Newton, Host of SXList.com
james@sxlist.com 1-619-652-0593 fax:1-208-279-8767
SX FAQ / Code / Tutorials / Documentation:
http://www.sxlist.com Pick faster!
Paul Baker refers to " the $044 (swap osc pin with w) " but Peter said it "shifts the oscillator pin into/outof W"
Does anyone know what direction it shifts or if it actually swaps a bit in/out of W?
Can it be used in any other situation than with an internal osc?
Doesn't the SXKey provide the clock when it is connected and so this must be using one of the osc pins while the key drives the other one right?
How does the direction get set? In or Out? Is one OSC pin always the In and the other the Out? If so, how does the SXKey continue to provide a clock while at the same time transmitting data?
Could it be that one OSC pin is an input while the other is high and and output when the other is low?
Ok, thats enough questions on this one.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
---
James Newton, Host of SXList.com
james@sxlist.com 1-619-652-0593 fax:1-208-279-8767
SX FAQ / Code / Tutorials / Documentation:
http://www.sxlist.com Pick faster!
Comments
I'm not so sure how this instruction can be of much use, other than programming.
I'm going from long-term memory here, so I stand to be corrected. I suppose the only sure way is to test the beast.
That instruction works when the SX is put into the programming mode;·forcing one (can't recall which) of the OSC pins high and then wiggling the other OSC pin 8 times. That I believe then maps the toggled pin into W, at I suspect bit0, but don't recall. And yes, I do believe it was a swap rather than a shift. The pin is able to operate bi-directionally, permitting the (SX-Key) debugger to write or read data through that OSC pin.
There ar a bunch more valid questions you raise James, and I don't recall just now.
Looks like I better have a go at finding out definitively.
Could take a little while, so please be patient....I DO have a full-time job.
Perhaps someone elso has these facts at the ready????
Peter
Some clarifications are in my post under "the secret SX instructions".
Peter