BTCR_DISPENA_OV0
c |= (BTCR_DISPENA_OV0 | BTCR_DISPENA_OV1) << 24;
c &= ~((BTCR_DISPENA_OV0 | BTCR_DISPENA_OV1) << 24);
((BTCR_DISPENA_OV1 | BTCR_DISPENA_OV0) << 24));