AMBA AHB-lite preventing a bus lock

[shaiko]

Hello,

I have a question about a master to slave transfer on an AHB-lite bus.
Suppose, an AHB-lite master initiates a transfer to an AHB-lite slave.
If the slave can respond at once, everything goes fine.
But if it takes the slave many cycles to do the job the slave must issue an HREADY='0' for as long as it's busy - This action would cause a bus lockup for a long period!

On a full AHB bus (not AHB lite) the way around it is using split transfers, but an AHB-lite doesn't support split transfers...Is there a way around it?

 

[ljxpjpjljx]

you can add extra logic to wrapper the AHB-lite bus to support the operation!

 

[tariq786]

If this causes a bus lock up, it is still according to the protocol. I mean there is no violation of the protocol.

Are you having any problems with this? Please explain in detail.

 

[shaiko]

Hi tariq786,

I don't have a protocol problem - everything works fine. However, I was looking for an additional functionality - what I need can be best described as "slave generated interrupts".
I now see that the AHB doesn't have inbuilt support for such action and it seems like slave polling is the only option - or implementig the interrupts via out of bus logic.

It's a shame that such support isn't part of the protocol itself.

---------- Post added at 22:14 ---------- Previous post was at 22:12 ----------