RBUF_HFB_FILTER_EN_SHIFT
reg |= hfb_enable << (RBUF_HFB_FILTER_EN_SHIFT + 1);
reg |= (1 << ((f_index % 32) + RBUF_HFB_FILTER_EN_SHIFT)) |
reg &= ~(1 << ((f_index % 32) + RBUF_HFB_FILTER_EN_SHIFT));