Dear Sir or Madam:
We are having difficulty programming the QSPI flash and then let Vybrid (MVF50NS151CMK50) boot from it. Our planned flow is as follows.
- The board is set by pull-up and pull-down resistors to boot per RCON and from QSPI.
- BOOT_MODE[1:0] = 0b10
- RCON1 is pulled low
- RCON4-7 pulled low
- For a PCBA that has not been programmed, the Vybrid will invoke the serial downloader. The MPU would be able to boot from USB.
- Once the QSPI flash on-board is programmed, power cycle the board.
- Upon POR, the Vybrid will scan the boot_mode pins and the RCON configuration. It will boot from QSPI accordingly.
However, this approach does not work as expected. Below is what we tried and saw.
- Configured the board for Boot Mode 0b10
- Connected USB cable & applied power
- Started ‘Vybrid MfgTool’ application
- MfgTool sees board connected and begins programming, but reports QuadSPI initialization failed
On the other hand, with the board configured for Boot Mode 0b00 this procedure works properly – MfgTool is able to program the QuadSPI on the board. The catch for Boot Mode 0b00 is that we are unable to blow the efuses to set Vybrid to boot from the QSPI flash. So even we can program it, Vybrid still cannot boot from the QSPI flash because Boot Mode is 0b00 and none of the efuses is blown.
Any suggestions or comments are greatly appreciated.