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EVE2 QSPI not responding
Posted: Thu Jul 18, 2019 3:18 pm
by broth1969
I have a EVE2-43A-BLM-TPN connected to our FPGA platform with Ambiq Micros MSPI quad master controller. Attached is the schematic connection through a 1.8V to 3.3V level shifter to the 20 pin FPC connector on J5. We cannot get any response from the FT812 on the EVE2 module when we try to read the electronic ID at 0xC0000-0xC0003. The MISO pin just stays low like nobody is home. RESET_n is high and Power is good. Any ideas?
-Blake Roth
Re: EVE2 QSPI not responding
Posted: Thu Jul 18, 2019 4:22 pm
by Daniel Divino
Hey there Broth!
Welcome to the forums!
Could you provide the initialization code that you are using for your setup?
In all of our demos we send the following to the display:
Code: Select all
Gpu_Hal_SetSPI(host, GPU_SPI_SINGLE_CHANNEL, GPU_SPI_ONEDUMMY);
/* Access address 0 to wake up the chip */
Gpu_HostCommand(host, GPU_ACTIVE_M);
Gpu_Hal_Sleep(300);
/* Read REG_CHIPID to confirm 0x7C is returned */
{
uint8_t chipid;
//Read Register ID to check if chip ID series is correct.
chipid = Gpu_Hal_Rd8(host, REG_ID);
while (chipid != 0x7C)
{
chipid = Gpu_Hal_Rd8(host, REG_ID);
delay(100);
}
printf("VC1 register ID after wake up %x\n", chipid);
}
Are you sending something similar?
Cheers,
Daniel
Re: EVE2 QSPI not responding
Posted: Mon Jul 22, 2019 2:41 pm
by broth1969
From software:
"According to the programmers guide, you need to send CLKEXT and ACTIVE commands before trying to read any registers. I’ve added this code now, but I’m still getting 0’s back for both the REG_ID and for the DeviceID reads."
We have the trace in a Saleae logic analyzer file. Can you look at that file format if I email it or something?
…
Does the backlight or analog voltages need to be connected? This seems fairly basic and we have 2 brand new displays we are trying.
Thanks
-Blake
Re: EVE2 QSPI not responding
Posted: Mon Jul 22, 2019 3:17 pm
by Daniel Divino
Hi Blake,
Could you specify which demo you are referencing?
It is recommended that the ACTIVE command is sent to wake up the Graphics controller.
We could try taking a look at the file here, though we don't actually use a Saleae logic analyzer.
While the backlight doesn't need to be connected, 3V3 power should be supplied through pin 1 on the EVE2 board.
Were you able to test the display's communication using one of our USB2SPI bridges, or an Arduino Scoodo Shields?
Cheers,
Daniel
Re: EVE2 QSPI not responding
Posted: Tue Jul 23, 2019 1:50 pm
by broth1969
I don't have any of the USB2SPI bridges, or an Arduino Scoodo Shields....yet. I'd hope to not have to go that route but if I do need to can you suggest part numbers and the best place to order these host examples?
Here are some screen shots of the initialization sequence from our logic analyzer traces. The display does seem to be responding now that the command sequence is correct but, the values it is returning do not jive with the datasheet.
-Blake
Re: EVE2 QSPI not responding
Posted: Tue Jul 23, 2019 2:22 pm
by broth1969
After slowing the SPI clock down below 11Mhz for initialization we have a backlight and are reading the DEV_ID correctly!