# Form `XFX` — XFX — Fixed (SPR/TBR/CR-field access)

## Bit Layout

| Bits | Field | Meaning |
| --- | --- | --- |
| 0–5 | `OPCD` | primary opcode (31) |
| 6–10 | `RT` | destination / source GPR |
| 11–20 | `spr/tbr/FXM` | SPR/TBR number (byte-swapped halves) or CR field mask |
| 21–30 | `XO` | extended opcode |
| 31 | `—` | reserved |

## Instructions Using This Form

<!-- GENERATED: BEGIN -->

| Mnemonic | Opcode | Group | Description |
| --- | --- | --- | --- |
| [`mtcrf`](../control/mtcrf.md) | `0x7c000120` | control | Move to Condition Register Fields |
| [`mfspr`](../control/mfspr.md) | `0x7c0002a6` | control | Move from Special-Purpose Register |
| [`mftb`](../control/mftb.md) | `0x7c0002e6` | control | Move from Time Base |
| [`mtspr`](../control/mtspr.md) | `0x7c0003a6` | control | Move to Special-Purpose Register |

<!-- GENERATED: END -->