Background programming refers to the ability to program the flash without interrupting the SRAM configuration. During background programming the SRAM contents are left intact and the device continues to function normally. This feature is typically associated with the internal flash, however it is also possible to perform background programming of the external SPI flash device connected to the sysCONFIG port of LatticeXP2.
To enable background programming the dual purpose SPI sysCONFIG pins have to be retained after configuration. This is controlled by the PERSISTENT option on other families, the equivalent to persistent option for LatticeXP2 is SLAVE_SPI_PORT, it can be enabled using the preference(.lpf) file.
Preference syntax:
SYSCONFIG SLAVE_SPI_PORT=ENABLE ;