the problem of TMS320C6203 boot

Started by April 26, 2010
Dear All, Now I have a problem about TMS320C6203 boot in my project.

We design a C6203 DSP system, with a fifo connecting to the DSP
and the external interface by XBUS.Sometiems TMS320C6203 cannot boot correctly.Power on 20 times,one time TMS320C6203 cannot boot .
when not boot,I connected the target board to the CCS with XDS560 JTAG emulator.Flash data read by CCS all are 0XFF.I have a reset switch,when I push switch,
reset signal from FPGA is 0,to reset DSP.but DSP cannot boot correctly.
I use reset cpu in CCS.The program transfer from flash is ok and DSP boot correctly.
I see the datasheet.when reset,XD[0..31] will load to DSP.XD31 Should be pull down,in datatsheet.but in my project XD31 is not connect.

I need your help. How can I boot the DSP correctly? Thank you.