HPI Interface connectivity with GPMC bus

USHA M

Other Parts Discussed in Thread: OMAPL138, AM3352

Hi,

I want to interface TMS320C674x DSP with AM335x. HPI lines of DSP will be connected to GPMC lines of AM335x. But I need to use MMC2 signals pin-muxed on some of the GPMC Address and control lines.

I saw some threads saying UHPI_HHWIL should be connected to GPMC_A[1] and UHPI_HR/W to GPMC_DIR . GPMC_A[1] and GPMC_DIR are pin muxed with MMC2 signals.

Can I connect UHPI_HR/W to GPMC_nWE?
Is there any other option to connect UHPI_HHWIL to some other GPMC address line (eg.GPMC_A[0]) or any other signal?
Can UHPI_HCNTL[1:0] pins be connected to GPMC_A[27:26]?

Please suggest.

Thanks,

Usha

over 9 years ago

0 Senthilkumar Srinivasan over 9 years ago

TI__Mastermind 43660 points

Hello Usha,

The HPI to GPMC interface is already discussed in below links.

http://e2e.ti.com/support/arm/sitara_arm/f/791/t/254235.aspx

http://e2e.ti.com/support/dsp/omap_applications_processors/f/42/t/208659.aspx

http://e2e.ti.com/support/dsp/davinci_digital_media_processors/f/717/p/126590/453920.aspx

You are requested to post the same query in AM335x Sitara forum as well to get the recommendations on connecting other GPMC signals to HPI interface.

Regards,

Senthil

0 USHA M over 9 years ago in reply to Senthilkumar Srinivasan

Intellectual 290 points

Hi Senthil,

Thanks for your response. I have already gone through those threads.

I want to know is there any option to connect UHPI_HHWIL to any other signal except GPMC_A[1]? Because I want to use other pin-mux option of GPMC_A[1] (i.e., as MMC2_DATA0).

Thanks,

Usha

0 Senthilkumar Srinivasan over 9 years ago in reply to USHA M

TI__Mastermind 43660 points

Hello Usha,

As per the connection diagram shown below, the UHPI_HHWIL can be connected to GPMC_A[4] pin also.

Even though the connection diagram highlighted the OMAPL138 device, it is applicable for C674x too.

Regards,

Senthil

0 USHA M over 9 years ago in reply to Senthilkumar Srinivasan

Intellectual 290 points

Hi Senthil,

Is this connectivity verified in any other design?

In AM3352 TRM Section 7.1.3.1, it is mentioned that GPMC_A[11] should not be used in GPMC Multiplexed Address/DATA 16-bit mode.

GPMC_A[5] and GPMC_A[4] are used for UHPI_R/W and UHPI_HHWIL signals. Whether these signals are configured as GPIOs or as GPMC pins?

Do we need to consider any timing constraints?

Thanks,

Usha

0 Senthilkumar Srinivasan over 9 years ago in reply to USHA M

TI__Mastermind 43660 points

Hello Usha,

Yes, the connectivity is verified in one of our customer's design,

In AM3352 TRM Section 7.1.3.1, it is mentioned that GPMC_A[11] should not be used in GPMC Multiplexed Address/DATA 16-bit mode.

Yes, the above mentioned statement is applicable for 16-bit memory interface in multiplexed mode.

GPMC_A[5] and GPMC_A[4] are used for UHPI_R/W and UHPI_HHWIL signals. Whether these signals are configured as GPIOs or as GPMC pins?

With reference to the above connectivity diagram, the UHPI_R/W signal can be connected with either GPMC_A[5] or GPIO1[21]. But UHPI_HHWIL signal must be connected with GPMC_A[4] only.

You could find the attached GPMC to HPI interface timing analysis document useful for your understanding on timing constraints.

7462.AM335x GPMC to OMAP-L13x UHPI Timing Analysis_v3.pptx

If you still need more clarification on GPMC interface, i would suggest you to post your query on AM335x forum (below link) for better response.

http://e2e.ti.com/support/arm/sitara_arm/default.aspx

Regards,

Senthil