Hi,
In AMBA AHB:-
For two clock cycle SPLIT or RETRY response, hgrant must be low after 1st clock cycle of SPLIT or RETRY response.
q) For two clock cycle ERROR response, is it mandatory of hgrant must be low after 1st clock cycle of ERROR response?
q) May i know the state(low/high) of hgrant signal in two clock cycle response?
q) If i want to continue the remaining transfers after receiving ERROR response of a burst, is it necessary to rebuild the transaction or not?
q) with out of rebuild transaction, is it possible to continue the transfers w.r.to ERROR response?
I guess you say by seeing the 3.12.4 of AMBA™ Specification (Rev 2.0) [ARM IHI 0011A].
3.12.4 Bus handover with split transfersThe protocol requires that a master performs an IDLE transfer immediately after receiving a SPLIT or RETRY response allowing the bus to be transferred to another master. Figure 3-20 shows the sequence of events that occur for a split transfer.
As the result, there is no such rule as you mentioned wrt HGRANT.It would be a matter of the arbiter.
Best regards,Yasuhiko Koumoto.
Thanks for your reply.
when two clock cycle ERROR response is in progress, HGRANT signal in first cycle and 2nd cycle depends upon the arbiter.
That is there is no rule of hgrant must be low after first cycle of ERROR response.
May i know above understanding is correct?
yes, you may.
By the way, I wonder why you will care the HGRANT value.
I think you say about an AHB slave but HRGANT will be related to an AHB master.
It would be reasonable of an arbiter to make HGRANT low at the SPLIT response, because SPLIT means the the current target slave cannot perform the current master and the master should be changed to the other masters.
The AHB specification only says, the current master is recommended to make HTRANS IDLE if the response was SPLIT or RETRY.
Best regards,
Yasuhiko Koumoto.
Thanks a lot.