TMS320C6657: TMS320C6657 EMIF problem

user5992872

Part Number: TMS320C6657

The EMIF read time is measured with an oscilloscope. As shown, a high level indicates a wait time between reading and reading, and a low level indicates a reading time. According to the EMIF user manual of the C6657, I have set the EMIF A3CR register Turn Around cycles to 0, but still have a wait time of 200ns. Further debugging found that the wait time does not change regardless of the configuration of the TA segment of the A3CR register. The wait time between reading and reading is much longer than the time it takes to read.

1. Is there any way to configure the wait interval between reading and reading?

over 5 years ago

0 Yordan Kovachev over 5 years ago

TI__Guru**** 161600 points

Let me check this one and I will update the thread.

Best Regards,
Yordan

0 user5992872 over 5 years ago in reply to Yordan Kovachev

Prodigy 140 points

Yordan，Thank you.

Waiting for your further answer.

0 user5992872 over 5 years ago in reply to user5992872

Prodigy 140 points

Can someone help me with this problem?

0 Yordan Kovachev over 5 years ago in reply to user5992872

TI__Guru**** 161600 points

Hi,

First of all apologies for the delay.

As you can see in the register description for the TA bit field:
"This delay is not incurred between a read followed by a read, or a write followed by a write to the same chip select. The reset value is 4 cycles"

You could try changing the SETUP & HOLD times in the ASYNC 3 Config Register to try and manipulate the strobe period. Or try to enable the extended wait mode of operation of the emif (see section 3.8 of the user guide).

Best Regards,
Yordan

0 user5992872 over 5 years ago in reply to Yordan Kovachev

Prodigy 140 points

HI，Yordan.

Thank you for your answer.

I have configured the R_SETUP bit to be 1, the R_STROBE bit is 2, and the R_HOLD is 1. Now the oscilloscope shows that the low-level read time is about 40us and the high-level wait time is about 140us.That is, one cycle is 180us and the reading speed is still a bit slow.

So in addition to further reducing the read time, is there any way to reduce the waiting time?

Best wishes.

0 Yordan Kovachev over 5 years ago in reply to user5992872

TI__Guru**** 161600 points

Hi,

Not sure there is. There is a default waiting time (setup, hold time), which you cannot reduce. Take a look at the Async X Config Register, X=1..4.

Best Regards,
Yordan

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TMS320C6657: TMS320C6657 EMIF problem