SCA_TCNTL0
subcnt = sca_read_2(sc, SCA_TCNTL0);
(void)sca_read_2(sc, SCA_TCNTL0);
subcnt = sca_read_2(sc, SCA_TCNTL0);
bus_space_write_2(iot, sca_ioh[0], SCA_REG(SCA_TCNTL0), 0x0);
tmp = bus_space_read_2(iot, sca_ioh[0], SCA_REG(SCA_TCNTL0));
bus_space_write_2(iot, sca_ioh[0], SCA_REG(SCA_TCNTL0), 0x55AA);
tmp = bus_space_read_2(iot, sca_ioh[0], SCA_REG(SCA_TCNTL0));