CHN_F_BITPERFECT
CHN_F_BITPERFECT : 0;
#define CHN_BITPERFECT(c) ((c)->flags & CHN_F_BITPERFECT)
wrch->flags &= ~CHN_F_BITPERFECT;
wrch->flags |= (enabled != 0) ? CHN_F_BITPERFECT : 0x00000000;
rdch->flags &= ~CHN_F_BITPERFECT;
rdch->flags |= (enabled != 0) ? CHN_F_BITPERFECT : 0x00000000;