TCO1_CNT
cnt = ichwd_read_tco_2(sc, TCO1_CNT) & TCO_CNT_PRESERVE;
ichwd_write_tco_2(sc, TCO1_CNT, cnt & ~TCO_TMR_HALT);
cnt = ichwd_read_tco_2(sc, TCO1_CNT) & TCO_CNT_PRESERVE;
ichwd_write_tco_2(sc, TCO1_CNT, cnt | TCO_TMR_HALT);