Cache tag permission control register 1.
| PRO_I_TAG_RD_ACS | Setting to 1 permits read access to Icache tag memory. |
| PRO_I_TAG_WR_ACS | Setting to 1 permits write access to Icache tag memory. |
| PRO_D_TAG_RD_ACS | Setting to 1 permits read access to Dcache tag memory. |
| PRO_D_TAG_WR_ACS | Setting to 1 permits write access to Dcache tag memory. |