hi all can anyone tell me what's the following CSL function have done hMcbsp1 = MCBSP_open(MCBSP_PORT1, MCBSP_OPEN_RESET); if I use folowing code to reset MCBSP1 in C5509a , my program can not generate interrupt. SPCR1_1 = 0x0000; SPCR2_1 = 0x0000; but use MCBSP_open my program interrupt well. all the other code i have not use CSL function.