Can all registered uses please login, even just for a few minutes..
It helps build a picture where our "good traffic" is coming from..
Thanks :)

TF CD32 Riser Revision 2 Design Complete

TF CD32 Riser

Moderators: terriblefire, Terriblefire Moderator

terriblefire
Admin sponsor
Admin sponsor
Posts: 5687
Joined: Mon Aug 28, 2017 10:56 pm
Location: Glasgow, UK

Re: TF CD32 Riser Revision 2 Design Complete

Post by terriblefire »

arkadiusz.makarenko wrote: Mon Oct 12, 2020 11:13 pm That is what I did try, already.
I need to measure exti latency....

I even can't read meaningful data from the bus. :(
Time for a break and regroup I think. :D ... it was worth a try. (Need to get a little bit better with verilog)
EXTI latency is not the issue. It could sit there for a month... no issues. You want it to be short for performance but You read the mouse and joystick once every 1/50th of a second and you read the RTC once at boot time. So speed isnt critical.

The issue is that when you ACK the ARM is still putting data on the bus. So the next instruction fetch crashes.

I suspect the bus isnt getting tristated again.

You could try put data on the bus... when you ack latch it into the cpld... then read it from the cpld on some other random address.
———
"It is not necessarily a supply voltage at no load, but the amount of current it can provide when touched that
indicates how much hurting you shall receive."
User avatar
arkadiusz.makarenko
Moderator Team
Moderator Team
Posts: 1371
Joined: Wed Jun 19, 2019 7:36 am
Location: Edinburgh

Re: TF CD32 Riser Revision 2 Design Complete

Post by arkadiusz.makarenko »

terriblefire wrote: Mon Oct 12, 2020 11:37 pm
arkadiusz.makarenko wrote: Mon Oct 12, 2020 11:13 pm That is what I did try, already.
I need to measure exti latency....

I even can't read meaningful data from the bus. :(
Time for a break and regroup I think. :D ... it was worth a try. (Need to get a little bit better with verilog)
EXTI latency is not the issue. It could sit there for a month... no issues. You want it to be short for performance but You read the mouse and joystick once every 1/50th of a second and you read the RTC once at boot time. So speed isnt critical.

The issue is that when you ACK the ARM is still putting data on the bus. So the next instruction fetch crashes.

I suspect the bus isnt getting tristated again.

You could try put data on the bus... when you ack latch it into the cpld... then read it from the cpld on some other random address.
Now I got triggered. :D

I must do something really stupid there...
Do not trust people. They are capable of greatness.
~ Stanislaw Lem
User avatar
arkadiusz.makarenko
Moderator Team
Moderator Team
Posts: 1371
Joined: Wed Jun 19, 2019 7:36 am
Location: Edinburgh

Re: TF CD32 Riser Revision 2 Design Complete

Post by arkadiusz.makarenko »

BUAHAHAHA!!!!! It's ALIVE :D

20201013_103803.jpg
20201013_103803.jpg (416.25 KiB) Viewed 3682 times

Edit: I was not handling DSACK correctly. This one hold 0/1 high till ARM tell it to change DTACK0 to low.

And on ARM side I do reprogram gpio back to open drain before I send ACK to CPLD. It must takes few cycles before it actually happens so cd32 have enough time to latch data.
Do not trust people. They are capable of greatness.
~ Stanislaw Lem
terriblefire
Admin sponsor
Admin sponsor
Posts: 5687
Joined: Mon Aug 28, 2017 10:56 pm
Location: Glasgow, UK

Re: TF CD32 Riser Revision 2 Design Complete

Post by terriblefire »

Nice work. Now you can do everything you need from ARM. just used different INTSIG for different addresses.
———
"It is not necessarily a supply voltage at no load, but the amount of current it can provide when touched that
indicates how much hurting you shall receive."
terriblefire
Admin sponsor
Admin sponsor
Posts: 5687
Joined: Mon Aug 28, 2017 10:56 pm
Location: Glasgow, UK

Re: TF CD32 Riser Revision 2 Design Complete

Post by terriblefire »

terriblefire wrote: Tue Oct 13, 2020 11:07 am Nice work. Now you can do everything you need from ARM. just used different INTSIG for different addresses.
If you tell me all the pcb changes needed for the RTC and Vcap i'll update the github repo
———
"It is not necessarily a supply voltage at no load, but the amount of current it can provide when touched that
indicates how much hurting you shall receive."
User avatar
arkadiusz.makarenko
Moderator Team
Moderator Team
Posts: 1371
Joined: Wed Jun 19, 2019 7:36 am
Location: Edinburgh

Re: TF CD32 Riser Revision 2 Design Complete

Post by arkadiusz.makarenko »

terriblefire wrote: Tue Oct 13, 2020 2:28 pm
terriblefire wrote: Tue Oct 13, 2020 11:07 am Nice work. Now you can do everything you need from ARM. just used different INTSIG for different addresses.
If you tell me all the pcb changes needed for the RTC and Vcap i'll update the github repo
I will, but need to get my head round all RTC options. Just touched the subject few months ago. Need to refresh my memory on it.
Do not trust people. They are capable of greatness.
~ Stanislaw Lem
terriblefire
Admin sponsor
Admin sponsor
Posts: 5687
Joined: Mon Aug 28, 2017 10:56 pm
Location: Glasgow, UK

Re: TF CD32 Riser Revision 2 Design Complete

Post by terriblefire »

arkadiusz.makarenko wrote: Tue Oct 13, 2020 3:28 pm I will, but need to get my head round all RTC options. Just touched the subject few months ago. Need to refresh my memory on it.
No worries. I think you mentioned you needed another oscillator?

I'll sort the video out and let you get back to me on the oscillator.
———
"It is not necessarily a supply voltage at no load, but the amount of current it can provide when touched that
indicates how much hurting you shall receive."
terriblefire
Admin sponsor
Admin sponsor
Posts: 5687
Joined: Mon Aug 28, 2017 10:56 pm
Location: Glasgow, UK

Re: TF CD32 Riser Revision 2 Design Complete

Post by terriblefire »

I'm considering this part for buffering the video output..

https://uk.rs-online.com/web/p/video-buffers/4972511/

and

https://uk.rs-online.com/web/p/video-buffers/1627539/

May end up going with a part that JLCPCB has supply of rather that the "best" chip.

e.g.

https://datasheet.lcsc.com/szlcsc/3PEAK ... 155447.pdf
———
"It is not necessarily a supply voltage at no load, but the amount of current it can provide when touched that
indicates how much hurting you shall receive."
terriblefire
Admin sponsor
Admin sponsor
Posts: 5687
Joined: Mon Aug 28, 2017 10:56 pm
Location: Glasgow, UK

Re: TF CD32 Riser Revision 2 Design Complete

Post by terriblefire »

I have pushed the changes for the Vcap to github. let me know if you want the crystal changed etc.
———
"It is not necessarily a supply voltage at no load, but the amount of current it can provide when touched that
indicates how much hurting you shall receive."
terriblefire
Admin sponsor
Admin sponsor
Posts: 5687
Joined: Mon Aug 28, 2017 10:56 pm
Location: Glasgow, UK

Re: TF CD32 Riser Revision 2 Design Complete

Post by terriblefire »

We need to figure out what you meant here..

https://www.exxosforum.co.uk/forum/viewt ... d32#p37462

LSE oscillator was missing i think?
———
"It is not necessarily a supply voltage at no load, but the amount of current it can provide when touched that
indicates how much hurting you shall receive."
Post Reply

Return to “TF CD32 Riser”