Hello Andreas,

Thanks for your reply.

Prathap

On Mon, Nov 9, 2015 at 1:27 PM, Andreas Hansson <[email protected]>
wrote:

> Hi Prathap,
>
> Command-bus contention is intentionally not modelled. The main reason for
> this is to keep the model performant. Moreover, in real devices the command
> bus is typically designed to _not_ be a bottleneck. Admittedly this choice
> could be reassessed if needed.
>
> Andreas
>
> From: gem5-users <[email protected]> on behalf of Prathap
> Kolakkampadath <[email protected]>
> Reply-To: gem5 users mailing list <[email protected]>
> Date: Monday, 9 November 2015 at 18:25
> To: gem5 users mailing list <[email protected]>
> Subject: [gem5-users] Modelling command bus contention in DRAM controller
>
>
> Hello Users,
>
> After closely looking at the doDRAMAccess() of dram controller
> implementation in GEM5, i suspect that the current implementation may not
> be taking in to account the command bus contention that could happen if
> DRAM timing constraints take particular values.
>
> For example in the below scenario, the queue has two closed requests one
> to Bank1 and other to Bank2.
>
> Request1@Bank1 (PRE-ACT-CAS) --> Request2@Bank2 (PRE-ACT-CAS)
>
> Lets say tRP(8cycles), tRCD(8cycles), tCL(8cycles), and tRRD(8 cycles). In
> this case ACT of R2 and CAS of R1 becomes active at the same time.
> At this point one command needs to be delayed by one clock cycle. I don't
> see how simulator is handling this?  If the simulator is handling this,
> could someone please point me to the code snippet where this is handled.
>
>
> Thanks,
> Prathap
>
>
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