We have a custom board based on the imx6ulevk, but unfortunately we can not boot it. We have tried/verified the following:
- PMIC set rails correctly: (VDD_AR_SOC_IN=1.40V, VDD_HIGH_IN=3.29V, VDD_SNVS_IN=3.01V, NVCC_ENET=3.28V, NVCC_SD=3.3V, NVCC_UART=3.28V, DRAM_VREF=0.675V, NVCC_RAM=1.35V, NVCC_NAND=3.28V, NVCC_GPIO=3.28V, VDD_ADC_3P3=3.3V, NVCC_LCD=3.28V)
- LDOs in processor seems to work (ARM_CAP=1.17V, SOC_CAP=1.17V, VDD_HIGH_CAP=2.5V, NVCC_PLC=1.12V, VDD_SNVS_CAP=1.12V)
- Oscillators 32kHz and 24MHz are running
- When connected to PC via USB, PC reports Unknown Device after reset is released, there is USB bus activity about 3 seconds after reset release.
- UART-1 is connected to terminal program (115200bps), nothing comes out here
- We see that POR (pin P8) is de-asserted after PMIC is started, we have also manually released reset via a reset switch on the interface board
- ONOFF button logic seems to work, turns off PMIC after 5 sec press and re-starts PMIC after 1 sec press
- We can connect to A7-core with a Segger J-LINK connected to JTAG pin-header correctly (we have no debug environment in place yet to manipulate core through JTAG though)
- We have tested various BOOT-MODE configurations
- We do not see any activity on DDR3-RAM
- System draws just 0.4W after reset release
- PMIC type is MC34PF3000A7EP
- Processor type is MCIMX6Y2CVM08AA
We're expecting the board to be able to boot using SD-card (verified on the EVK), or to show up as a HID-device in the PC environment.
Would be extremely thankful for any guidance!!!