SBP_INFILTER
sbdsp_mix_write(sc, SBP_INFILTER,
(sbdsp_mix_read(sc, SBP_INFILTER) & ~SBP_IFILTER_MASK) |
mixval = sbdsp_mix_read(sc, SBP_INFILTER) & ~SBP_IFILTER_MASK;
sbdsp_mix_write(sc, SBP_INFILTER, mixval);
sbdsp_mix_read(sc, SBP_INFILTER) & SBP_IFILTER_MASK;