AN3349

Limitations

Doc ID 018511 Rev 2

11/13

5.6

Parallel instructions

The converter supports parallel instructions. However, there are certain rare parallel

instructions which are supported in Byte Craft but not in the eTPU compiler assembler. The

Byte Craft compiler supports jmp and end sub-instruction as part of the same parallel

instruction, but the eTPU compiler doesn't support such a combination since both jmp and

end

change the program flow. If the original code contains such an instruction it will be

converted without any errors, but the assembler will report an error when the converted

instruction is assembled.

5.7

Warnings

5.7.1

ld/ldm

When loading variables which are allocated on the channel the ldm operator should be

used, and when loading global variables the ld operator should be used. The converter

does not distinguish between those variable and therefore always uses the ldm operator

when converting instructions which load C variables. In such cases the following warning is

printed: "Instruction has been converted by default to ldm but might be

ld depending on the label's value

".

5.7.2

Hex directives

The converter supports hex directives which begin with %hex in Byte Craft, and are

converted to .word directives in eTPU compiler assembly. However, a warning is still

printed when these directives appear because the converter doesn't analyze their meaning.

Since there is usually a reason that the original instructions appear in hex instead of Byte

Craft assembly, it is recommended to review the converted directive and possibly rewrite the

instruction in eTPU compiler assembly.