pasm to clpru porting guide for PRU

[Mark A. Yoder]

I'm converting some PRU assembly code from pasm to clpru and finding there are some differences.  An earlier thread noted some differences between the two (Use LDI, not MOV for loading constants for example).

Has anyone made a porting guide?  For example:

#define CH1BIT r30.t8 

converts to

   .asg    r30.t8,     CH1BIT

Thanks...

--Mark

[Mark A. Yoder]

Well I couldn't find one, so I made one.  http://elinux.org/EBC_Exercise_30_PRU_porting_pasm_to_clpru

Please add to it.

--Mark

[Greg]

There is in fact difference notes published by TI.  Perhaps difficult to locate!

Look in the README.txt file located in the command line package.

This is in the directory ti-cgt-pru_2.1.2.

Here is an excerpt:

Assembler

-------------------------------------------------------------------------------

Instructions

-------------------------------------------------------------------------------

The syntax for instruction mnemonics is very similiar to the existing PASM

assembler. Exceptions are listed here:

1. MOV instruction

   MOV is only supported for register to register moves. The LDI instruction

   must be used to load a literal into a register. 

2. LDI instruction

   LDI can only be used to load a 16-bit constant into a register. To load a

   32-bit constant, you must use the LDI32 instruction.

3. MVI instruction

   MVI is only supported on core revisions 2 and 3. The existing PASM assembler

   supports the instruction in a limited form for v1 using pseudo operations.

4. ZERO instruction

   ZERO is only supported on v2 and v3 cores. For v1, the user should use

   LDI r0, 0.

5. LFC, SFC, and SCAN

   These instructions are not supported. If support is needed we can add them.

6. Operands with a '&' prefix

   The existing PASM assembler accepts operands with or without the & 

   symbol: LBBO &r0 or LBBO r0. The assembler in this release requires the

   & for these operands. 

There is a bit more than the above.

Regards,

Greg

[Mark A. Yoder]

I found a porting guide here: http://processors.wiki.ti.com/index.php/PRU_Assembly_Instructions#pasm_vs._clpru

--Mark