Re: [Gems-users] SINGLE_ACCESS_L2_BANKS Usage

[Mike Marty <mikem@xxxxxxxxxxx>]

> I was wondering whether  "SINGLE_ACCESS_L2_BANKS" ruby parameter defined
> in rubyconfig.defaults is used or not. I was looking for any usage of
> that but I did not find any (I am using Gems 1.3). If it is used, can
> anyone plz tell where is it?
If you can't find it anywhere else, the parameter is probably unused.

> I have another question about L2 access interleaving. Lets assume
> L2_RESPONSE_LATENCY is set to 8 cycles. For a GETS request (hit) at
> cycle t, L2 will send the data to output after 8 cycles at t+8. Within
> this 8 cycles (after the transition) can any other request (say another
> GETS at t+1 cycle) be processed? When the data for next GETS will be in
> output port?
Depends on the protocol.  First, L2_RESPONSE_LATENCY is only used by a few 
protocols (the ones with CMP in the names).  Second, L2_RESPONSE_LATENCY 
only models the fixed access latency.  There is additional latency 
incurred in the interconnect to get the data back to the L1 controller 
(assuming a protocol with seperate L1 and L2 controllers).  As far as 
allowing another GETS, it depends on the protocol.  If the SLICC 
specification indicates that a GETS hit enters a transient state, then it 
might not allow another request until the transient state leaves.
--Mike