Hi Toshi. Class 4 TIN 3 is a DAE (Data Access Asynchronous Error). DEADD will contain the address of the error. The actual instruction that caused the error is probably two or three instructions prior to the trap return address, because the TriCore uses Store Buffers to perform writes in the background. See 6.6.3 Store Buffers on page 228 of tc23x_tc22x_um_v1.1.pdf.
Erm. I don't think you understand the problem.
This problem can be replicated by single-stepping the instructions in the PLS debugger.
So there is some sort of debugger kernel running on the target.
Therefore, the few instructions before this instruction would be in the debugger kernel.
So by your logic, the problem is in the debugger kernel, which seems unlikely.
12 Core Debug Controller (CDC)
12.1 Run Control Features
• Single-Step support in hardware.
It's trapping on an access to an ASCLIN register.
I just checked, and the TC234LA does have the LIN module.
So this is weird.
Have you enabled the peripheral via ASCLIN0_CLC=0 (usually handled by IfxAsclin_setEnableModuleRequest)? If not, none of the ASCLIN registers (except CLC) will be visible in the debugger, or writable by the application.