[sdiy] Xpander

[Richie Burnett]

With shared RAM between multiple CPUs don't you then have to implement bus arbitration to prevent collisions?

High speed UART or SPI seems simpler to me.

-Richie,


Sent from my Xperia SP on O2

---- Tom Wiltshire wrote ----

>
>> On 18 Oct 2020, at 21:07, Gordonjcp <gordonjcp at gjcp.net> wrote:
>> 
>> On Sun, Oct 18, 2020 at 12:20:00PM +0100, Tom Wiltshire wrote:
>>> The Prophet T8 worked the same way, with the main processor writing to a common RAM area shared with the voice (“final”) processor.
>>> 
>>> Given the speed of serial comms at the time, it makes a lot of sense. In many ways it *still* makes a lot of sense.
>> 
>> I don't know, the Juno 106 communicates between the main CPU and the voice CPU at MIDI speeds but with only two-byte messages.
>> 
>> Nobody's ever accused the 106 of being laggy.
>
>Fair enough. The truth is that humans are really slow, so parameter updates don’t have to be that fast. As long as those note on/off messages get through in a timely manner, probably no-one will notice.
>
>Still, parallel comms is always going to be faster, and I like the “transparency” of using a shared RAM to get data from one system to the other. It’s quite neat, in a rather 1980’s way!
>
>
>_______________________________________________
>Synth-diy mailing list
>Synth-diy at synth-diy.org
>http://synth-diy.org/mailman/listinfo/synth-diy