SVF files generated by iMPACT to Erase the ISF flash on a Spartan-3AN FPGA will not erase all sectors if Power-of-2 addressing is enabled in the flash. This can lead to programming failures using SVF, ACE and XSVF programming. The issue is that the Sector Erase algorithm assumes the factory-default addressing mode rather than Power-of-2 and so will not address all sectors. A blank check will fail and a readback will show some sectors are not erased. This issue will be masked on new devices as the flash is shipped by Xilinx blank. This issue will only effect ISF flash which has been set to Power-of-2 mode manually to program the OTP bit on the flash. The issue only affects SVF/XSVF/ACE mode. There is a potential for failures at manufacturing or during field upgrades using
XAPP058 (XSVF player),
XAPP424 (ACE player), third-party SVF/STAPL-based solutions, or custom JTAG where new images have been deployed to update previously programmed Spartan-3AN devices.