Exception Packet For Return Stack Match Might Return Incorrect [E1:E0] Field

Versal AI Core Series Production Errata (EN313)

Document ID
Release Date
1.6 English

AMD Answer 73148

When an abort or trap is taken at the target of an indirect branch matching the return stack value in the core ETM, an exception packet might be generated with the 2-bit field [E1:E0] = 2'b10, which implies an address element before the exception element. When there is a trace return stack match, an address element should not be generated before the exception element. With [E1:E0] = 2'b10, the external trace analyzer might read the trace packet sequence to expect an address element output before the exception element and not complete the stack pop, which is incorrect. The correct value in the [E1:E0] field in the exception packet for this case, should be 2'b01.

This is a third-party errata (Arm, Inc. 1185472); this issue will not be fixed.