I've encountered a strange problem working with SPORT on Blackfin 512F. When I used SPORT0_RX to receive data manually in the interrupt service routine I got the constant sequence 0x00450045 derived from SPORT0_RX register. I tried to use external and internal RCLK and RFS in different variations, even changed PORT_MUX and PORT_FER to disconnect SPORT data input from board completely, but got the same result, even the same sequence read from SPORT0_RX. But when I decided to use DMA for receive operation, it went through, I got it to work with no other changes! I received the right data form input data pin. Now I am facing the same kind of problem with transmit operation, but unfortunately now it comes with DMA too, I'm getting the constant signal from the TX data output no matter what I do to the DMA and SPORT configurations or to the output data in my program, except I can turn the signal on and off by turning SPORT enable bit, but no other changes, I can't affect the data coming out of the chip. Could you please help me to work this all out.
Thanks in advance