KS_ISR
status = ks8851_rdreg16(ks, KS_ISR);
ks8851_wrreg16(ks, KS_ISR, status);
ks8851_wrreg16(ks, KS_ISR, ks->rc_ier);
ks8851_wrreg16(ks, KS_ISR, 0xffff);