CLA delay function

Alexandros Tsoupos

Prodigy 180 points

Hello to all,

Is there any function that can accurately delay the CLA in F28377S for a specific amount of time like the DELAY_US ?

If not, do you have any suggestions on how would I implement this?

Thanks,

Alexandros

over 9 years ago

0 Gautam Iyer over 9 years ago

Guru 192875 points

Hi Alex,

CLA is clocked at the same frequency as the main CPU. You should be able to use DELAY_US routine itself.

Regards,
Gautam

0 Alexandros Tsoupos over 9 years ago in reply to Gautam Iyer

Prodigy 180 points

I had the impression that the routine DELAY_US() is executing CPU asm commands.
How can it be used to delay the CLA without any modification?

Regards,
Alex

0 Alexandros Tsoupos over 9 years ago in reply to Alexandros Tsoupos

Prodigy 180 points

As expected, executing the raw DELAY_US() function inside the CLA doesn't work. Does anyone know if there is a simple solution to this or do I have to write a cla assembly function?

Thanks, Alex

0 Vishal_Coelho over 9 years ago in reply to Alexandros Tsoupos

TI__Mastermind 20850 points

Hi Alex,

DELAY_US wont work on the CLA. that function is written in C28x assembly. you will have to write something in CLA assembly. It probably wont be very cycle accurate

; \brief CLA delay function
; \param[in] N counter in MR0
;
; This function basically loops "N" times
; cycles (SYSCLK) = 2(prologue) + 8*N + 4(epilogue)
;
    .global _delay_cla
    .sect "Cla1Prog"
_delay_cla: 
    .asmfunc
    MMOVIZ  MR1, #0 ; decrement value
    MMOVXI  MR1, #1 
_delay_cla_loop:
    MSUB32  MR0, MR0, MR1 ; set ZF when MR0 is 0
    MNOP
    MNOP
    MNOP
    MBCNDD  _delay_cla_loop, NEQ
    MNOP
    MNOP
    MNOP
    MRCNDD  UNC
    MNOP
    MNOP
    MNOP
    .endasmfunc

You can probably define this in a .asm file and declare a prototype "void delay_cla(int32_t N);" in a header file that will be included by the CLA. It should take 2+4+8N sysclk cycles, so you would have to define a macro that translates microseconds to "N"

0 Alexandros Tsoupos over 9 years ago in reply to Vishal_Coelho

Prodigy 180 points

Thanks, this is extremely useful to me!

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CLA delay function