SH3_MMUCR
#define SH3_TLB_DISABLE *(volatile uint32_t *)SH3_MMUCR = SH3_MMUCR_TF
r = _reg_read_4(SH3_MMUCR);
_reg_write_4(SH3_MMUCR, SH3_MMUCR_AT | SH3_MMUCR_TF);