REG1
CSR_WRITE_1(sc, REG1, CSR_READ_1(sc, REG1) | Tx_Chn_Int_Md |
CSR_WRITE_1(sc, REG1, CSR_READ_1(sc, REG1) | TriST_INT);
CSR_WRITE_1(sc, REG1, CSR_READ_1(sc, REG1) & ~TriST_INT);