4.11. ACE CR channel

Table 4.11 shows the ACE CR channel protocol rules.

Table 4.11. ACE CR channel

AssertionDescriptionAMBA AXI and ACE Protocol Specification reference
ACE_ERRM_CRVALID_X

When not in reset, a value of X on CRVALID is not permitted

C2.3.3
ACE_ERRS_CRREADY_X

When not in reset, a value of X on CRREADY is not permitted

C2.3.3
ACE_ERRM_CRVALID_STABLE

When CRVALID is asserted, it must remain asserted until CRREADY is asserted

C3.7
ACE_ERRM_CRRESP_STABLE

CR payload signals must remain stable while CRVALID is asserted and CRREADY is de-asserted

C3.7
ACE_ERRM_CRRESP_DIRTY

When CRVALID is asserted and CRRESP[2], PassDirty, is asserted, then the CRRESP[0], data transfer, signal must be asserted

Table C3-22
ACE_ERRM_CRRESP_SHARED

When CRVALID is asserted in response to an AC transfer, where ACSNOOP was ReadUnique, CleanInvalid, or MakeInvalid, the CRRESP[3], IsShared, signal must be de-asserted

C3.7
ACE_ERRM_CR_ORDER

CRVALID must not be asserted before the corresponding AC handshake

Figure C3-1
ACE_ERRM_CRRESP_X

When CRVALID is asserted, a value of X on CRRESP is not permitted

C3.7
ACE_ERRM_CRRESP_DVM

A DVM response must use CRRESP[4:0] = 5'b000x0

C12.3.4
ACE_ERRM_CRRESP_DVM_ERROR

An error response is not permitted for a:

  • DVM Sync

  • DVM Complete

  • DVM Hint.

C12.3.4, C12.7.6
ACE_RECS_CRREADY_MAX_WAIT

CRREADY should be asserted within MAXWAITS cycles of CRVALID being asserted

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