TMS320F28379D: HLC PUSH Behavior

Ed Sanders

Greetings,

I am using the HLC to push data which is retrieved at a later time. In reading the TRM, I find that I am confused about some things.

Section 26.4.6.4 Operation of the PUSH and PULL Instructions: The first paragraph says that the PUSH buffer is mapped at address offset 0x200. From what is this offset applied?
Section 26.6.3.8 CLB_BUF_PTR: The information on the PUSH field indicates that it is the number of values which have been pulled from the buffer by the HLC. Is this correct, or is it the number which have been pushed by the HLC? My observations say it’s the latter. Same question for the PULL field.
Typo in paragraph 3 of 26.4.6.4. “the CPU can at any time” s.b. “the CPU at any time”.

Thank you,

over 5 years ago

0 Himanshu Chaudhary60 over 5 years ago

TI__Expert 3720 points

Hi,

The subject matter expert assigned to this thread is out of office this week due to the the US holiday so you may not get a qualified answer until Tuesday or Wednesday next week. I apologize for the delay.

Regards,

Himanshu

0 Peter Galicki over 5 years ago in reply to Himanshu Chaudhary60

TI__Expert 8105 points

Hello,

I received your post and am looking at it now. Should be able to respond shortly

Regards,

Peter

0 Nima Eskandari over 5 years ago in reply to Peter Galicki

TI__Guru 52080 points

1. That is the offset from the CLB BASE address, if you use driverlib CLB functions this is already handled for you.

2. So everything is from the C28x side. PULL is from the C28x side, which corresponds to how many times the C28x can pull, which corresponds to how many times the HLC has PUSHED!

Nima

0 Ed Sanders over 5 years ago in reply to Nima Eskandari

Genius 4205 points

Hi Nima,

1. OK

2. I’m still confused. In the TRM, section 26.6.3.8, the text for the PUSH and PULL fields is from the HLC’s point of view. Furthermore, our experience indicates that when the HLC executes a PUSH instruction, LogicCtrlRegs.CLB_BUF_PTR.PUSH increments. To make this observation, the HLC is setup as follows:

One event on e0.
program0 has one instruction which is a PUSH instruction.

When the event occurs, it is observed that LogicCtrlRegs.CLB_BUF_PTR.PUSH increments the expected amount. LogicCtrlRegs.CLB_BUF_PTR.PULL is unchanged. This pattern repeats when the test is run again.

So it seems that if this was from the C28x's point of view, that the PULL field should have incremented.

Thanks,

0 Nima Eskandari over 5 years ago in reply to Ed Sanders

TI__Guru 52080 points

Ed,

I tried this as well and seems that you are right.

I will place a note in the TRM.

Nima

0 Ed Sanders over 5 years ago in reply to Nima Eskandari

Genius 4205 points

Thank you Nima.

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TMS320F28379D: HLC PUSH Behavior