1. Home
  2. Embedded Programming
  3. Rabbit : RCM2200 I/O mapped peripherals

Rabbit : RCM2200 I/O mapped peripherals

Hello all,

I need to attach a collection of UARTS to an RCM2200. 8 bits of data and 4 bits of address are brought off of the RCM module along with /IORD and /IOWR. I can't see any other relevant signals.

Am I correct in thinking that I need to qualify /IORD and /IOWR appropriately - to generate an individual /IORD and /IOWR for each peripheral - I plan to use PortB as the address qualifier, probably with some HC138s.

On the HC138s, /IORD will feed /G2A, Port B will feed A/B/C and Y0..7 of the HC138 then become /IORD_0..7. Same applies (on a different HC138) to /IOWR to generate 8 individual strobes, /IOWR_0..7.

I assume that I will need to write some assembler (last time I checked, Dynamic C didn't support I/O directly) to do the I/O bashing.

Any thoughts or words of advise before I climb into this next design ?

Thanks,

Mark.

Reply to
Mark Aren
Loading thread data ...

Mark

There is a very active Rabbit user e-mail list on yahoo which you may want to join.

I'm not sure if I understood your question right, but if it's about generating individual chipselect signals, then you can use PortE for this purpose. It can be configured to generate up to 8 chipselects which are mapped into the external address space of the Rabbit. Using DynamicC for the external IO is no problem these days although writting assembly will result in significantly faster code.

HTH

Markus

Reply to
Markus Zingg

Marcus,

Many thanks.

Mark.

Reply to
Mark Aren

ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.