SH3_MMUDA
r = _reg_read_4(SH3_MMUDA | a);
dae = _reg_read_4(SH3_MMUDA | entry_idx);
r = _reg_read_4(SH3_MMUDA | a);
_reg_write_4(SH3_MMUDA | a, newd);
_reg_write_4(SH3_MMUDA | a, 0);