The LatticeiCE40 device has the following programming modes :
- SPI Master: In this mode, a standard SPI Flash is connected to the Device , and the device boots from the external SPI Flash using SPI Master configuration Interface. This is the best method for prototype phase where you can experiment with different designs/bitstreams.
- NVCM: The iCE40 devices contains an One Time Programmable on-chip Non Volatile Configuration Memory (NVCM) and if configured, the device boots from it. This is a fast and secure mode of bringing the device into user mode(active with user program) and used for mass production. The NVCM is ONE TIME PROGRAMMABLE.
- Slave SPI: In this mode an external CPU or a microcontroller programs the device in SPI mode, the device being the Slave.