I noticed a mistake in your configuration (XPERCON =0x0080): In order to to be able to use X-Bus peripherals, XPEN bit in SYSCON register and the peripheral enable bit (XASCEN in our case) & XMISCEN bit in XPERCON register must be set. So, could you please set XMISCEN bit in XPERCON register and let me know how it goes? Please refer to the discussion forum on the follwowing link: http://www.stmcu.com/forums-cat-2864-5.html Regards, Najoua. [ This message was edited by: Najoua on 08-09-2006 15:01 ]