Can I program the External SPI Flash using Slave SPI Interface in LatticeECP3 device?
Yes, the SPI FLASH Connected to the LatticeECP3 device can be programmed using a CPU or Micro-controller through Slave SPI Interface of the device. Care should be taken that :
1. The LatticeECP3 device configuration mode is SPI or SPIm.
2. The Slave SPI Interface is enabled through SSPI Persistent option or device is erased.
For prototyping, use ispVM system software or Lattice Diamond Programmer. After selecting the appropriate device, set the Device Access Option to "SSPI Flash Programming" in the Device Information/Device Properties window. Select any operation such as SPI Flash Erase, Program,Verify and any Flash device listed in the tool. The programming software will now behave as a Master SPI controller with Lattice's ispDownload cable Fly-wires behaving as SPI interface pins. The mapping is:
TDI -> SISPI
ISPEN -> CSSPISN
TCK -> CCLK
TDO -> SOSPI
VCC -> VCC
GND -> GND
For a user who wants to develop their own algorithm, please refer to FPGA-TN-02136 LatticeECP3 Slave SPI Port User Guide apart from TN1169 Lattice ECP3 sysCONFIG Usage Guide for help. The exact details of commands are described in the section Class E Command Waveforms in FPGA-TN-02136.