Hi We work with a XCF01S and a Spartan 3 XC3S200. JTAG works with 2.5V, Spartan Vcco (INIT_B and DIN/D0) has 3.3V. The connections between XCF and Spartan are according the application note for 3.3V output (INIT_B) to 2.5V input CE/RES.
Programming the Flash and booting from Flash works fine. Programming the FPGA works only, when we have the same code in the Flash. When we try to load a different code (as is in the Flash) per JTAG to the FPGA, the FPGA doesn't start up.
Does anybody know what's going wrong?