4.3.3 Swapping the SPI Flash Memory Devices
The EV42J24A development board comes with four 3.3V Quad SPI memory devices installed in the Flash memory sockets. Some customers may wish to use specific SPI Flash devices from other memory vendors or to install 1.8V devices. If a decision is made not to use the default memory devices, it is the responsibility of the customer to ensure compatibility.
3.3V SPI Flash Devices
To upgrade to a different vendor while maintaining 3.3V operation, power down the board, remove the existing SPI Flash devices, and replace them with the new memory devices. Follow the procedures defined in the previous sections for powering up the board and programming the Flash devices with the DediProg programmer.
1.8V SPI Flash Devices
The CEC173x supports two SPI banks of up to two chips each. Each bank can support either 1.8V or 3.3V SPI chips. The voltage on each bank can be controlled separately. J10 is used to connect VTR1, which powers SPI Channel 0. J12 is used to connect VTR2, which powers SPI Channel 1. The CEC1736 is a flow-through data path; therefore, the supporting application processor interface must also supply the correct voltage signals for the selected SPI. For the EV42J24A, the support application processor is the MEC1723, which is connected to VTR2. Its supply voltage is controlled by jumper J14. J12 and J14 must always be set to the same supply voltage level.
To configure the board to run with 1.8V QSPI Flash devices, some jumper positions must be modified. Prior to making these modifications, power down the board by removing all power to it. Then, follow the jumper modifications specified in the R2 or R3 revision subsections below.
After modifying the desired jumper settings, follow the procedures defined in 4.1 Powering the CEC173x Evaluation Board and 4.3 Updating the External SPI Flash Firmware for powering up the board and programming the Flash devices with the DediProg programmer.