DLPC3470: DLPC3470 Not Booting

Scott Grodevant

Part Number: DLPC3470
Other Parts Discussed in Thread: DLPA2005,

Hi All,

I am bringing up a projector board that uses the DLPA2005 and DLPC3470. I was having an issue with the crystal oscillator, but that turned out to be a defective board since the second board's oscillator is running fine.

Now I believe the 3470 is trying to boot but not getting the appropriate data from Flash. I don't see the 3470 sending a read command to Flash since the DI signal is always low. The Flash ROM, W25Q32 (133 MHz) have been pre-programmed with code Kyle sent me (ASIC routing option 4).

Can you tell me the details of the boot process and what happens in the event of errors?

Below I've shown the key Flash signals: CS, DO and CLK. As I said above, DI is always low. All the traces are 50us/cm.

Thanks,

Scott

over 5 years ago

0 Scott Grodevant over 5 years ago

Intellectual 925 points

0 Scott Grodevant over 5 years ago in reply to Scott Grodevant

Intellectual 925 points

I have repaired that first board with the dead oscillator. The oscillator now runs, but I don't see any data on its DI line either. Is there something I'm missing?

Thanks,
Scott

0 Kyle Rakos over 5 years ago in reply to Scott Grodevant

TI__Mastermind 20045 points

Hi Scott,

I'm glad you were able to fix the oscillator problem. Could you re-upload the first images? It appears there was an error when trying to get them uploaded on E2E.

Either way - are you setting PROJ_ON (GPIO_08) high to start the bootup process?

Thanks,
Kyle

0 Scott Grodevant over 5 years ago in reply to Kyle Rakos

Intellectual 925 points

Hi Kyle,

I've attached the images, but they are unremarkable.

Yes, I am alternately setting and clearing PROJ_ON every 10 seconds or so.

When set, I see CS (on the Flash chip) pulse low for about 225 us, then pulse high for 10 us (or so). During the chip-select time SCK runs at 1.4 MHz for the entire select time. This repeats as long as PROJ_ON is high. The Flash on one of the two boards outputs a couple of bits of data on it's DO line at the beginning of the 225 us select period, the other board's DO line sits low all the time. Neither board's DI line shows any activity. Both signals sit low all the time. I assume there's no (or limited) DO activity because the 3470 isn't issuing a read command to Flash. Just my hunch.

Thanks,

Scott

0 Scott Grodevant over 5 years ago in reply to Scott Grodevant

Intellectual 925 points

Hi All,

Any thoughts on this?

Thanks,

Scott

0 Kyle Rakos over 5 years ago in reply to Scott Grodevant

TI__Mastermind 20045 points

Hi Scott,

Sorry for the delay. Could you please clarify what each waveform is referencing? Some better waveforms may help me understand what you are describing on the flash lines.

Thanks,
Kyle

0 Scott Grodevant over 5 years ago in reply to Kyle Rakos

Intellectual 925 points

Hi Kyle,

Left-to-right the waveforms are chip select, DO and SCK. I didn't post DI because it always sits low. Scales are 50us/div and 2V/div. My second board's waveforms are identical except there's no activity on DO, it is always low.

I would expect the DLPC3470 to clock out a read command (3) at the beginning of it's boot sequence to retrieve code from Flash, but neither board shows any high bits on the DI signal. The clock is 1.4 MHz.

Thanks,
Scott

0 Kyle Rakos over 5 years ago in reply to Scott Grodevant

TI__Mastermind 20045 points

Hello Scott,

It appears like the flash is never responding to the read command. Could you please share your schematic for me to take a look at? Could you also please confirm the flash was programmed. Perhaps you could even try the default DLPC3470 EVM firmware just to make sure the other firmware doesn't have an issue. You can find that at www.ti.com/.../DLP2010EVM-LC

Thanks,
Kyle

0 Scott Grodevant over 5 years ago in reply to Kyle Rakos

Intellectual 925 points

Hi Kyle,

Flash is *never* getting a read command. I have carefully monitored the Flash DI signal (along with clock) and see no activity on DI of either of my two boards. Accordingly there is no meaningful activity on DO of Flash.

I have physically removed Flash from one of the boards and verified its content in the programmer.

Best I can tell, something is preventing the 3470 from issuing the Flash Read command when it boots. Is there some possible board fault that explains this?

I posted the schematic in this thread: e2e.ti.com/.../787168.

Thanks,
Scott

0 Kyle Rakos over 5 years ago in reply to Scott Grodevant

TI__Mastermind 20045 points

Hello Scott,

Thanks for reminding me of your posted schematic. I took a look at the flash hookup and it looks like you may have accidentally swapped the SPI0IN and SPI0OUT ports. The DLPC3470 IN should be connected to the flash DO and the DLPC3470 OUT should be connected to DI of the flash.

I would recommend seeing if there is a way to quickly modify this on the board to confirm.

Thanks,

Kyle

0 Scott Grodevant over 5 years ago in reply to Kyle Rakos

Intellectual 925 points

Thanks a million Kyle. There have been lots of thing swapped in the design, so this comes as no surprise! I'll give that a try tomorrow and check the box if indeed it is my problem, although I can't believe it isn't at this point.

Scott

0 Kyle Rakos over 5 years ago in reply to Scott Grodevant

TI__Mastermind 20045 points

Hi Scott,

Happy to help! Let me know if it ends up fixing the problem!

Thanks,
Kyle

0 Scott Grodevant over 5 years ago in reply to Kyle Rakos

Intellectual 925 points

Hi Kyle,

Just to confirm that was the issue. I'm still not seeing PROJ_IRQ drop after the 3470 loads its code, but I am seeing a burst of activity on DO, so I'm probing around to see what's happening.

Thanks again for seeing what I didn't!

Scott

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DLPC3470: DLPC3470 Not Booting