DLPC6540: The spi communication between DLPC6540 and DLPA3005

Hello User,

Welcome to the E2E forum and thank you for your interest in DLP® technology.

I would recommend you to also check and measure the power up sequence on the DMD and DLPC6540. Please refer to DLPC6540 datasheet section 6.12 and DLP471TP datasheet section 9.1 and figure 9-1. Please provide the captures and we can take a look for next step troubleshoot. 

Regards,

Lori 

Thanks for your reply.

I have previous checked the powerup sequence of DLPC6540，it works as datasheet says. and if I manually disconnect the spi line by removing end resistor, DLPC6540 continues working. The USB control is ok. Of course DMD and LED are not working.

I will check for the DMD power up sequence.

Hello Zeguang,

Thanks! We can look into more when you confirm the DMD power up sequence.

Regards,

Lori 

Sorry to reply so late for my personal matters.

I have checked that DLPA3005 does not out put Vbias, Voffset and Vreset for DMD. So it seems that DLPC6540 has not come to the stage of powering up DMD. It turns down before that. I wonder what does the sent spi commonds means?

Hello Zeguang,

For further debugging, can you please measure and provide the waveform of DMD_LS lines, including WDATA, RDATA, and CLK?

Regards,

Lori 

Hello Lori,

Waveform of DMS_LS lines is as the following. Yellow is CLK_P, magenta is WDATA_P, cyan is RDATA. CLK_P remain high for a short while then return to low. No signal on RDATA. It seems that something wrong with DMD?

Hello Zeguang,

Thank you for the information! 

I need to look into more and get back to you by the end of next week. 

Regards,

Lori 

Hello Lori,

Thanks for your reply.

The bandwidth of the oscilloscope that I used is only 70MHz. so maybe this is the reason why it showd no RDATA sigal.

I have replace DMD and DMD socket. The problem is still there.

And I wonder which comes first, the DMD start to work or the illuminating led start to lit? 

Hello Akhil, 

I have measure the Powerup sequence of DLPA3005 according to Figure 7-1 in DLPA3005's datasheet. PWR_6 and  DMD_VOFFSET, DMD_VBIAS, DMD_VRESET do not come out. What fault could it be? How can I get fault status

Hello Zeguang,

Do you use the PWR6 General purpose buck converter in your design? 

If yes, and the PWR6 does not power up properly or a certain fault condition occurs, then this would pull down the INT_Z signal. 

You can use GUI -> Advanced Mode -> Commands -> Debug -> DLPA3005 Register to read the following registers:

1. 0x0C 

2. 0x27

3. 0x28

4. 0x29

5. 0x2A

Please refer to the DLPA3000 Datasheet section 8.5 Register Maps, it's the same as DLPA3005 for the above registers that I mentioned.