|ARM Technical Support Knowledge Articles|
Applies to: PL301 AMBA 3 HP Matrix
We have configured one of the slave interfaces of the PL301 to use the AHB_LITE_MASTER protocol. We observe that the HRESP signal is only one bit wide, while according to the AHB protocol, it has to be 2 bits.
Is there any configuration we are missing which is causing this port mismatch?
AHB-Lite (AMBA 3.0) does not support the SPLIT and RETRY slave responses that are supported in full AHB (from AMBA 2.0).
Looking at the HRESP signals in full AHB:
00 - OKAY
01 - ERROR
10 - RETRY
11 - SPLIT
Because RETRY and SPLIT are not supported, the only possible responses are OKAY and ERROR (which can be determined using only bit 0 of HRESP).
Therefore, if you have an HRESP signal elsewhere in your system that is 2 bits wide, you can connect only bit 0 to your AHB-Lite master.
Did you find this article helpful? Yes No
How can we improve this article?