TMS320F28069: Sine and cosine function - long exection

Tomas,

I see that there are some warnings on lines 471 and 472. Can you tell me what they are?

Have you correctly included FPUmathTables in the linker cmd file if you are not using the ROMTABLES configuration?

From the map file, it looks like you are using the FastRTS APIs in ROM. In that case, you must also link the ROM symbols library.

If you plan to use the FLASH configuration, you must properly specify the load, run, start regions and memcpy the tables in runtime. Please refer to the examples for these configurations

Please get back to me with this information so we can narrow down the root cause.

-Shantanu

Shanty said:

I see that there are some warnings on lines 471 and 472. Can you tell me what they are?

Hello Shanty,

The warnings are "Description Resource Path Location Type function "cos" declared implicitly Dyno_main.c /Dyno_F28069 line 471 C/C++ Problem".

I did fix those warnings by including by the math header file (#include <math.h>). This has not changed the performance.

Shanty said:

Have you correctly included FPUmathTables in the linker cmd file if you are not using the ROMTABLES configuration?

The FPUmath table is included in the default linker file. From the file is seems that the these libraries are not copied to the target but instead called from ROM (NOLOAD).

I do not know what the ROMTABLES configuration even is. I searched the F28069 datasheet as well as the technical manual for this keyword nothing came up.

I am using FLASH, again using the standard memcpy function:

Shanty said:

In that case, you must also link the ROM symbols library.

If you plan to use the FLASH configuration, you must properly specify the load, run, start regions and memcpy the tables in runtime. Please refer to the examples for these configurations

Which are the specific examples I should look at? The FLASH_F28069 does not seem to have any pertinent code.

Thank you.

EDIT: it seems that even if running from ROM, the functions should not take 460 cycles but only <50.

Tomas,

I think I see the problem. You specified NOLOAD when allocating  the FPUMathTables, which means that you are using the tables in ROM. For this, you need to add the ROM symbols library as well so that your application can use those tables. In this case, you do not need to memcpy from FLASH to RAM because you are using the tables in the ROM. The ROM symbols library can be found in c2000ware.

This is different when you load the tables in FLASH. In this case, you need to allocate the tables as follows: (Do not use NOLOAD in this case)

FPUmathTables : LOAD = FLASH_BANK0_SEC1,
                             RUN = RAMLS4,
                             RUN_START(FPUmathTablesRunStart),
                             LOAD_START(FPUmathTablesLoadStart),
                             LOAD_SIZE(FPUmathTablesLoadSize),

Then memcpy in the code as you specified. 

In your case, I suspect that the APIs may be using the standard RTS trig functions, which work without FPU leading to higher clock cycles. You can verify this as follows: 

Single assembly step into the cosine function call. Check if FPU32 instructions are being executed. Also check if the APIs are reading the values from the FPUMathTables locations for the computation. If these two cases are true, we may need to debug this further. 

-Shantanu

Shanty said:

FPUmathTables : LOAD = FLASH_BANK0_SEC1,
                             RUN = RAMLS4,
                             RUN_START(FPUmathTablesRunStart),
                             LOAD_START(FPUmathTablesLoadStart),
                             LOAD_SIZE(FPUmathTablesLoadSize),

Hello Shanty,

This has resulted in a number of issues during linking - apparently FLASH_BANK0_SEC1 and RAMLS4 are not defined in my default linker file provided by TI.

" 0
RUN = RAMLS4,
"../cmd/F28069.cmd", line 156: error: no valid memory range available for
placement of "FPUmathTables"
FPUmathTables : LOAD = FLASH_BANK0_SEC1,
"../cmd/F28069.cmd", line 156: error: program will not fit into available
memory, or the section contains a call site that requires a trampoline that
can't be generated for this section. run placement with alignment/blocking"

And below is the print out of the assembly - it seems to execute FPU instructions.

For my program, I started it from the provided code my the C2000 LaunchPad from ControlSuite.

However, you are referencing C2000Ware, which is unknown to me.

Can you provide me with a minimal functional example that I can load to see how to do configure my DSP correctly? 

Thanks,

Tomas

Tomas Sadilek said:

This has resulted in a number of issues during linking - apparently FLASH_BANK0_SEC1 and RAMLS4 are not defined in my default linker file provided by TI.

What I provided was an example. ControlSuite is deprecated. Please refer to the examples in C2000ware. You can find it in <c2000ware>/libraries/math/FPUFastRTS/c28/examples. The out of box examples are not for F28069x. So you will have to take any of the examples and port them over (by changing the device variable in project settings and using the memory configuration from sample linker command files in device_support). Everything will remain the same except the specific memory ranges. 

But regarding your screenshot, it looks correct and the correct API is being referenced. Can you assembly step through the function and look at the cycles (in CCS, run -> clock) to identify which instructions are contributing to the high cycle count. 

-Shantanu

Shanty said:

What I provided was an example. ControlSuite is deprecated. Please refer to the examples in C2000ware. You can find it in <c2000ware>/libraries/math/FPUFastRTS/c28/examples. The out of box examples are not for F28069x. So you will have to take any of the examples and port them over (by changing the device variable in project settings and using the memory configuration from sample linker command files in device_support). Everything will remain the same except the specific memory ranges. 

I have tried doing so and the results are not good.

The project is now using the correct linker files, though there was an error (TI ram funcs) so I had to google a bit and copy some code to the linker files.

The project now compiles.

However, when debugging, the example never makes it out from the setup function 

//
// Setup system clocking
//
FastRTS_Example_setupSysCtrl();

This is likely caused by the example itself (C:\ti\c2000\C2000Ware_3_02_00_00\libraries\math\FPUfastRTS\c28\examples\sin_f32) since it calls for a header file for a completely different processor (F28002x).

I have done exactly as you suggested but it seems that the examples cannot be easily ported to a different processor?

====

Coming back to the assembly, I have done as you asked - it seems that each assembly instruction takes much longer than anticipated.

Also notice the location of these instructions: 3F6xxx - they are all located in the flash memory. It seems that these functions need to be copied to RAM from flash.

But what is worse, the output is wrong too - the input angle is 0.0 so the cos output should be 1.0 but it is 0.0.

EDIT: I was actually able to fix this by including the 28069M header file instead of the 28069 header file. The trig functions now compute correctly but the execution still takes ~450 cycles each.