NAND now back at full speed. (measured at about 10 x faster on the 'scope). NAND_RNB needed a pull up, clearly we are now reading this in the NAND driver (nand_status(0)). (Note this is not a "real" resistor but a programmed one inside the FPGA). The CPLD .ucf file had one but the FPGA .ucf file did not. I'll check stuff in on Monday now... Regards David __________ Information from ESET Smart Security, version of virus signature database 5476 (20100924) __________ The message was checked by ESET Smart Security. http://www.eset.com