SCU_MAX_FRAME_BUFFER_SIZE
if (this_request->type.pio.pio_transfer_bytes < SCU_MAX_FRAME_BUFFER_SIZE)
this_request, data_buffer, SCU_MAX_FRAME_BUFFER_SIZE);
this_request->type.pio.pio_transfer_bytes -= SCU_MAX_FRAME_BUFFER_SIZE;
this_request->type.pio.current_transfer_bytes += SCU_MAX_FRAME_BUFFER_SIZE;