Hello,
We are trying to flash a TPS65981 through I2C. So far we have managed to update the firmware program on the device and update the flash using the Data and 4CC command registers over I2C.
What I have found is that if the flash is initially unprogrammed or completely erased (used the Flash Erase command in the TPS65981 Application Customization Tool on the TPS65981EVM), the device does not allow you to program the flash over I2C, and is generally unresponsive. All registers return a number of bytes equal to zero where it would normally return the size of the register (example DataX returns 0x40), and all data is zero and cannot be modified over I2C. This behaviour does not change until I use the Application Customization Tool to flash a project or binary, after which I am able to program (update) the firmware on the Flash from I2C.
My question is how are you supposed to go about flashing/programming this device initially? Is there an IO that must be manipulated to allow initial programming? My first thought was that it had to be over the SWD, but I can't find any connection from the FTDI chip to those nets in the schematic of the EVM board, which I am able to program initially over with the Application Customization Tool (USB connection). Does the initial programming have to be over SPI?
Thank you.
