SPI communication failed between DRV8303 and TMS320F28062F

 TMS320F28062F worked as master and DRV8303 as slave.In ccs 6.2,,the slave always received 0xFFFF when programme runed in full speed,however,when i set a breakpoint before the first transmiting command and then run in full speed or the programme runed in single step,i received the correct datas.Dose anyone know why this happens?please help me out

Please refer to:

http://e2e.ti.com/support/applications/motor_drivers/f/38/t/564251?tisearch=e2e-quicksearch&keymatch=DRV8303%20SPI