RTC On CD32 Riser

Help & news on accelerators from TF, Amiga, Atari, CD32 etc

Moderators: terriblefire, Terriblefire Moderator

Post Reply
go0se
Posts: 112
Joined: Sun Nov 25, 2018 7:55 pm

RTC On CD32 Riser

Post by go0se » Sun Jun 16, 2019 11:05 am

I've often seen casual feature requests for a RTC to be added to CD32 projects. I know this has been a suggested addition to TF boards and that TF has rightly pointed out that such a 'one time' feature should live on the riser rather than his cards.

On delving further into the idea it becomes clear that the CD32 doesn't provide any RTCCS/_IORD/_IOWR pins on the expansion or indeed a GAYLE chip that would allow straightforward integration of a design such as https://github.com/screwbreaker/OpenA1200RTC onto the riser PCB.

I assume additional circuitry is required to implement this missing logic. Does anyone know of any open projects that implement a RTC circuit on the CD32? I know expansions such as the SX1 have a RTC so it must be possible. I also know that the original Kipper riser proposed a RTC but it wasn't implemented for whatever reason so it might just be a dead end?

Any information or links to existing resources would be appreciated.

Cheers.

terriblefire
Moderator Team
Moderator Team
Posts: 1489
Joined: Mon Aug 28, 2017 10:56 pm
Location: Glasgow, UK
Contact:

Re: RTC On CD32 Riser

Post by terriblefire » Sun Jun 16, 2019 11:40 am

i'd use a XC9536XL chip to decode the address and use this circuit. The ata.v code in my sources will generate the IOR/IOW signals for you
Screenshot 2019-06-16 at 11.39.30.png
Screenshot 2019-06-16 at 11.39.30.png (247.43 KiB) Viewed 1036 times
———
I get cranky when asked to repeat myself.

go0se
Posts: 112
Joined: Sun Nov 25, 2018 7:55 pm

Re: RTC On CD32 Riser

Post by go0se » Sun Jun 16, 2019 12:12 pm

Excellent, I'll take a look at the sources. The addition of the small footprint CPLD suggested along with the added RTC circuit it might even be possible to prevent the riser PCB growing into an ugly monster! :) Cheers.

terriblefire
Moderator Team
Moderator Team
Posts: 1489
Joined: Mon Aug 28, 2017 10:56 pm
Location: Glasgow, UK
Contact:

Re: RTC On CD32 Riser

Post by terriblefire » Sun Jun 16, 2019 1:06 pm

If im honest.. i woudlnt just add this to the kipper riser..

I'd look at using an STM32 type chip with dual USB ports to let us add wireless mouse/keyboard and bluetooth game controllers to the CD32.

Then i'd probably use a VGA port etc to give a really worthwhile upgrade.
———
I get cranky when asked to repeat myself.

Post Reply

Return to “Terriblefire's channel”