CH_DX_CSO_ALPHA_FMS
cso = inw(TRID_REG(trident, CH_DX_CSO_ALPHA_FMS + 2));
outw(voice->CSO, TRID_REG(trident, CH_DX_CSO_ALPHA_FMS) + 2);
val = inl(TRID_REG(trident, CH_DX_CSO_ALPHA_FMS));