CCS 3.1 assembler issue with MPYSPDP?

Jaehoon Heo

I hope some authoritative person from TI can address my issue.

I am using CCS v3.1 to program C67x+ core, and facing a problem in using MPYSPDP instruction in .asm file(hand assembly). In my specific example, if I use following insruction:

MPYSPDP A29,A27:A26,A27:A26

It shows up in the disassembly window of the simulator as:

MPYSPDP A29:A28,A26,A27:A26

So, somehow the assembler seems to mix up the operand encoding. I tried to decode the opcode 0x0d6ba5b1 and it seems to match what the disassembly window show. If I try to swap operands like MPYSPDP A27:A26,A29,A27:A26, I get errors. Please help me so I can finish optimization.

over 14 years ago

0 George Mock over 14 years ago

TI__Guru**** 251580 points

This is almost certainly a bug in the CCS 3.1 disassembler. That is a very old version of CCS. I do not have it installed, so I cannot check to be sure. But I can tell you that 0x0d6ba5b1 is the correct opcode for that instruction, provided you intend it to run in parallel with the next instruction. If no instruction is in parallel, the correct opcode is 0x0d6ba5b0.

Thanks and regards,

-George

0 Archaeologist over 14 years ago in reply to George Mock

TI__Guru* 84285 points

This particular bug existed in the standalone disassembler (dis6x). It was known as both SDSsq45456 and SDSCM00005280, and it was fixed in June 2006. In the same timeframe, the fix was propagated to CCS. I don't know what version that translates to.

0 Jaehoon Heo over 14 years ago in reply to Archaeologist

Prodigy 80 points

Hi All,

Thank you for your correct advices. I could finish the optimization, working around the bug.

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CCS 3.1 assembler issue with MPYSPDP?