Hi,
Customer wants to know reserved illegal opcode, please help with relevant information.
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Hi,
Customer wants to know reserved illegal opcode, please help with relevant information.
Hello!
I read this situation other way, to me it looks that 0xC0 and 0x104 are not legal opcodes for the core. I mean there are many legal opcodes, defined in instruction set manual, but these two do not appear to be correct ones. Often that happens due to memory corruptions. It could be that program counter was corrupted, or it may happen that code segment was corrupted.
Hello Nancy,
Please check the memory map and see if your customer placed any code at location 0xc0000004. If yes, that means the memory was overwritten. If not, that most likely means that the program counter gets an invalid address.
Regards,
Jianzhong
Hi,
Thanks for reply.
Let me explain again. Customer wants to know about the details of specified opcodes reserved in the instruction set. These reserved opcodes are not disclosed in the instruction documentation, but can be executed in the processor without error. For example, the instruction 0x00000320, you can check the assembly form of this instruction in the disassembly window.
Hi Nancy,
Let me loop in our compiler team for further help.
Regards,
Jianzhong
HI Nancy,
What exact CCS version are they using and what device?
Are they using an old CCS version with the old simulator?
Are they using an old CCS version with the old simulator?
Yes, he uses CCS5.5. The device is tms320c6748.
The device is tms320c6748.
Are they using actual hardware? Or is it a simulator?
Hi,
They tried both in simulator and actual hardware.
After executing the command in the simulator, illegal opcode information will be printed out in the Console window.
Executing the same instruction in actual hardware will not print this information.
Nancy,
Are they asking for a list of all illegal opcodes on C6748?
Regards,
John
Nancy,
We do not have a list of invalid opcodes for C6748 in the tools team.
We believe that the simulator is doing some sort of lookup of valid codes and when it does not get a match it reports that the opcode is illegal. That lookup is not straightforward. Also that simulator is very old, unsupported and I do not have access to the source.
Regards,
John