ZHCSRQ4 august 2023 TPSM8S6C24
PRODUCTION DATA
| CMD Address | FAh |
| Write Transaction: | Write Word |
| Read Transaction: | Read Word |
| Format: | Unsigned Binary (2 bytes) |
| Phased: | No |
| NVM Back-up: | EEPROM |
| Updates: | At Boot-up |
PASSKEY sets a User Programmable 16-bit passkey to disable write access to EXT_WRITE_PROTECT and User Store Non-Volatile Memory (NVM). When PASSKEY is set to 0000h, access to STORE_USER_ALL is enabled and writes to PASSKEY will update the active register value for PASSKEY. When PASSKEY is set to a value other than 0000h during boot-up, write access to EXT_WRITE_PROTECT and STORE_USER_ALL is disabled until the 16-bit word stored in NVM at boot-up is written to PASSKEY.
If 3 writes to PASSKEY are received that do not match the passkey without receiving a write that does match the passkey, PASSKEY access will be locked and all future writes to PASSKEY will be treated as invalid until the device receives a Power On Reset
To protect against unauthorized access to PASSKEY, reading PASSKEY will not respond with the passkey value but a fixed 16-bit word response based on the state of the PASSKEY
1. 0000h - PASSKEY is Unlocked
2. 000Fh - PASSKEY is Locked and no invalid writes have been made
3. 001Fh - PASSKEY is Locked and one invalid write has been made
4. 002Fh - PASSKEY is Locked and two invalid writes have been made
5. 00FFh - PASSKEY is Locked and three or more invalid writes have been made
| 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 |
| RW | RW | RW | RW | RW | RW | RW | RW |
| PASSKEY | |||||||
| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
| RW | RW | RW | RW | RW | RW | RW | RW |
| PASSKEY | |||||||
| LEGEND: R/W = Read/Write; R = Read only |
Bit | Field | Access | Reset | Description |
|---|---|---|---|---|
15:0 | PASSKEY | RW | NVM |
Write: PASSKEY passkey Read: ? 0000h - PASSKEY is Unlocked ? 000Fh - PASSKEY is Locked and no invalid writes have been made ? 001Fh - PASSKEY is Locked and one invalid write has been made ? 002Fh - PASSKEY is Locked and two invalid writes have been made ? 00FFh - PASSKEY is Locked and three or more invalid writes have been made |