31.5.9 Feature Unlock Key REGISTER
- KEY can only be written when STATUS.BUSY=0.
- KEY resets to 0 (a valid lock code) on a successful write to CTRLA, SWAP or an unsuccessful write to any register (any write that sets KEYERR).
- KEY allows for multiple writes to configuration registers when using CFGKEY. To lock, write a Valid Lock Code to KEY.
- Byte and Half-Word writes are ignored but result in a bus error.
| Symbol | Description | Symbol | Description | Symbol | Description |
|---|---|---|---|---|---|
| R | Readable bit | HC | Cleared by Hardware | (Grey cell) | Unimplemented |
| W | Writable bit | HS | Set by Hardware | X | Bit is unknown at Reset |
| K | Write to clear | S | Software settable bit | — | — |
| Name: | KEY |
| Offset: | 0x20 |
| Reset: | 0x00000000 |
| Property: | R/W |
| Bit | 31 | 30 | 29 | 28 | 27 | 26 | 25 | 24 | |
| CODE[23:16] | |||||||||
| Access | W | W | W | W | W | W | W | W | |
| Reset | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |
| Bit | 23 | 22 | 21 | 20 | 19 | 18 | 17 | 16 | |
| CODE[15:8] | |||||||||
| Access | W | W | W | W | W | W | W | W | |
| Reset | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |
| Bit | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | |
| CODE[7:0] | |||||||||
| Access | W | W | W | W | W | W | W | W | |
| Reset | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |
| Bit | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | |
| FEATURE[7:0] | |||||||||
| Access | R/W/HC | R/W/HC | R/W/HC | R/W/HC | R/W/HC | R/W/HC | R/W/HC | R/W/HC | |
| Reset | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |
Bits 31:8 – CODE[23:0] This register is used to lock and unlock write access to other Flash Contoller SFR bits. The KEY state remains active until it is written to a Valid Lock Code or an CTRLOP is written. 0x91C32C = Valid Unlock code - Unlocks selected SFR(s) Others = Valid Lock Code - Locks all SFR protected by KEY register Note: KEY can only be written when BUSY=0. Note: KEY resets to 0 (a valid lock code) on a successful write to CTRLOP, SWAP or an unsuccessful write to any register (any write that sets KEYERR).
This register is used to lock and unlock write access to other FCW SFR bits.
The KEY state remains active until it is written to a Valid Lock Code or CTRLOP is written.
0x91C32C= Valid Unlock code - Unlocks selected SFR(s)
All Others = Valid Lock Code - Locks all SFR protected by KEY register
Bits 7:0 – FEATURE[7:0] This register is used to lock and unlock write access to other Flash Contoller SFR bits. Others = Invalid selection - Key Value set to 00 - Locks all SFR protected by KEY register Note: KEY can only be written when BUSY=0. Note: KEY reset to 0 (a valid lock code) on a successful write to CTRLOP, SWAP or an unsuccessful write to any register (any write that sets KEYERR).
This register is used to lock and unlock write access to other FCW SFR bits.
0x00= no selection, invalid selection, or invalid Key - Locks all SFR protected by KEY register
0x01= WRKEY Value: Unlock SFR bits associated with Write/Erase
0x02= SWAPKEY Value: Unlock SFR bits associated with Panel Swapping
0x04= CFGKEY Value: Unlock SFR bits associated with general Flash configuration
all other values: Invalid selection - Key Value set to 00 - Locks all SFR protected by KEY register
| Value | Name | Description |
|---|---|---|
| 0 | LOCKALL | No selection, invalid selection, or invalid Key - Locks all SFR protected by KEY register |
| 1 | WRKEY | WRKEY Value: Unlock SFR bits associated with Write/Erase |
| 2 | SWAPKEY | SWAPKEY Value: Unlock SFR bits associated with Panel Swapping |
| 4 | CFGKEY | CFGKEY Value: Unlock SFR bits associated with general Flash configuration |