On Mon, 2012-10-08 at 22:46 +0200, Franck Jullien wrote:
> Hi,
> 
> As I was investigating on an IC problem on my Altera board, I found a
> wrong behavior (that's what I think) on the wb_cyc_o output from the
> or1200_wb_biu.
> At some point, when the biu_cyc_i to the biu is desaserted, the biu
> fsm is still waiting for an ack from the wishbone and the biu_cyc_i
> desasertion is not followed to the wb side.
> 
> Attached patch fix this.

Hi,

just for curiosity as we recently faced the same "issue". Doesn't
de-asserting the cycle and strobe without waiting for the ack break the
protocol?
We had the case that a second level cache was connected at the BIU and
because of internal changes to the L1 cache the BIU incorrectly aborted
a transaction. As the fetching at L2 took kind of long the corresponding
ack was then incorrectly attributed to the next transaction of the BIU.
From what I see, the Bus Master can not easily abort a bus transaction
or am I wrong?

Bye,
Stefan

-- 
Stefan Wallentowitz                        _/       _/_/_/    _/_/_/
Institute for Integrated Systems (LIS)    _/         _/    _/     
Technische Universität München           _/         _/      _/_/  
D-80290 München                         _/         _/          _/ 
fon +49 89 289 22963                   _/_/_/_/ _/_/_/   _/_/_/

[email protected]                  http://www.lis.ei.tum.de

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