BT459_IREG_ID
vdac[BT459_REG_ADDR_LOW] = (BT459_IREG_ID & 0xff) |
((BT459_IREG_ID & 0xff) << 8) | ((BT459_IREG_ID & 0xff) << 16);
vdac[BT459_REG_ADDR_HIGH] = ((BT459_IREG_ID & 0xff00) >> 8) |
(BT459_IREG_ID & 0xff00) | ((BT459_IREG_ID & 0xff00) << 8);