Other Parts Discussed in Thread: AM3517
We have developed our board with AM3517 (marked as AM3517AZCNA) and have some issues with it. We also have AM3517EVM kit which works fine as expected with following tests.
As we tried to work with NAND flash memory via GPMC subsystem we have noticed that there is no activity on I/O lines. Further investigation gave some odd results.
According to document "AM3517/05 Sitara ARM Microprocessors" (SPRS550D) the only function of pad T3 is gpmc_wait0 - input. We have external pull-up to 3.3V via 10k resistor on this line and when reset button is pressed we have 3.3V on this line. After reset release it drops to 0V, disconnecting flash memory pin doesn't change anything.
As this might be some power distribution issue we have tried to test GPIO modules with JTAG and OpenOCD.
Looks like GPIO1 module works fine (pads Y1 - GPIO_0, Y4 - GPIO_2, AA1 - GPIO_3) but GPIO2 and higher do not: for example pad T4 - GPIO_63
Last things is: Y1 (gpio_0) and M1 (gpio_56) are routed to testpoints, voltage on Y1 is 3.29V regardless of reset button state, voltage on pin M1 is 3.29 if reset pressed and 3.24 if released.
