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Re: TF CD32 Riser Revision 2 Design Complete
Posted: 14 Oct 2020 09:55
by terriblefire
juz400 wrote: 14 Oct 2020 09:50
Is there space for buffering the H and V Sync signals like the Active 23wD to VGA adaptor has?
Have one of those adaptors but it puts a fair bit of weight on the Riser, with the adaptor and a chunky VGA cable it moves the top away from the CD32
making it a bit flakey in operation.
There is a reasonable amount of room here. its choosing the right chip. One that will not end up EOL next week is what is concerning me,.
Re: TF CD32 Riser Revision 2 Design Complete
Posted: 14 Oct 2020 10:15
by juz400
I built one in the 90`s for a mate so he could use an NEC mutlisync on his A4000, IIRC we need a schmitt trigger inverter?
These are brand spanky new from On-Semi, pretty cheap too or should I look for a Dual model?
https://www.mouser.co.uk/ProductDetail/ ... 52B7cs0%3D
Re: TF CD32 Riser Revision 2 Design Complete
Posted: 14 Oct 2020 12:08
by terriblefire
juz400 wrote: 14 Oct 2020 10:15
I built one in the 90`s for a mate so he could use an NEC mutlisync on his A4000, IIRC we need a schmitt trigger inverter?
These are brand spanky new from On-Semi, pretty cheap too or should I look for a Dual model?
https://www.mouser.co.uk/ProductDetail/ ... 52B7cs0%3D
You dont want to invert the signal if you simply want to use the D23 as many of us do.
Re: TF CD32 Riser Revision 2 Design Complete
Posted: 14 Oct 2020 18:08
by terriblefire
@arkadiusz.makarenko I have pushed all the changes to the branch. It includes a video buffer chip. Just needs checked over and we're good.
Capture.PNG
EDIT: What did you change the HSE XTal for ?
Re: TF CD32 Riser Revision 2 Design Complete
Posted: 14 Oct 2020 21:04
by arkadiusz.makarenko
terriblefire wrote: 14 Oct 2020 18:08
@arkadiusz.makarenko I have pushed all the changes to the branch. It includes a video buffer chip. Just needs checked over and we're good.
Capture.PNG
EDIT: What did you change the HSE XTal for ?
The same type, but 25Mhz.
This allows me to set up all clocks, including 48Mhz for USB. I am not sure if it will be 100% stable, as my stm32 Nucleo board was a little temperamental running 216Mhz saying that this board is very solid.
I had a look and initially I was a little bit worried about dropping number INTSIG, but then I realised that SPI lines can be used if those will not be in use.
LSI crystal footprint was little bit unusual as I always seen them in different cylindrical package ... I guess I spend too much time with cheap Chinese knockoffs :D
Re: TF CD32 Riser Revision 2 Design Complete
Posted: 14 Oct 2020 21:46
by terriblefire
arkadiusz.makarenko wrote: 14 Oct 2020 21:04
The same type, but 25Mhz.
This allows me to set up all clocks, including 48Mhz for USB. I am not sure if it will be 100% stable, as my stm32 Nucleo board was a little temperamental running 216Mhz saying that this board is very solid.
OK i'll use 25Mhz for the build.
I had a look and initially I was a little bit worried about dropping number INTSIG, but then I realised that SPI lines can be used if those will not be in use.
I've not removed any INTSIG lines.. instead i removed TXD/RXD from the ARM (that is the direct connection to the CD32 internal UART) and moved R/W, INTSIG8 and KB_DATA. DSACK0 has been dropped and A5 added. So things have moved but have not been lost.
LSI crystal footprint was little bit unusual as I always seen them in different cylindrical package ... I guess I spend too much time with cheap Chinese knockoffs :D
That may change but its the same package as the other one.
I think i'll order 5 assembled if you think this will work.
EDIT: updated the 32.Khz crystal footprint too.
Re: TF CD32 Riser Revision 2 Design Complete
Posted: 14 Oct 2020 23:02
by terriblefire
5 ordered..
Screenshot 2020-10-14 at 23.01.43.png
Re: TF CD32 Riser Revision 2 Design Complete
Posted: 14 Oct 2020 23:22
by arkadiusz.makarenko
terriblefire wrote: 14 Oct 2020 23:02
5 ordered..
Screenshot 2020-10-14 at 23.01.43.png
Wow, This went quickly!
Re: TF CD32 Riser Revision 2 Design Complete
Posted: 15 Oct 2020 01:23
by kulamario
Can I buy one for my self if is possible ?
Re: TF CD32 Riser Revision 2 Design Complete
Posted: 15 Oct 2020 08:41
by terriblefire
kulamario wrote: 15 Oct 2020 01:23
Can I buy one for my self if is possible ?
If it works you can get one of the 5 from me. I may send an extra to Arek and ask him to assemble for me as currently I have no solder station.