ST25TV

Luke_abc · ‎2024-01-26

Hi,

I want to know if there is a provision to lock an entire area in ST25TV tags. I can see from the datasheet that blocks 0 and 1 can be locked, but I cannot see anything for other blocks. I know that I can use a password to do same but I do not want to use passwords. Basically, I want to write to an area in the tag and make it non-editable forever. Is this possible ?

JL. Lebon · ‎2024-01-26

Hello,

For the ST25TV16K and ST25TV64K, it is not possible to lock more blocks than block 0 and 1.
Nevertheless, it is possible to do what you want to do, which is locking all the blocks permanently using the password mechanism.

If you look at the RFA1SS, RFA2SS etc. and in particular at fields PWD_CTRL_Ax, you can see that value 00b in this filed means: "RF user security session can't be opened by a password". If you combine this with field RW_PROTECTION_Ax=01b (write protection), it means that the corresponding memory area will be protected against write and there will be no way to unprotect it using a password. So, the write protection is permanent, which looks like what you are willing to do.

Off course, someone who knows the configuration password can still change those settings. If you don't want this to happen, you can lock the configuration (LOCK_CFG configuration byte).

Best regards.

View solution in original post

JL. Lebon · ‎2024-01-26

Hello,

It depends on what version (memory size) of ST25TV you are using. Is it ST25TV16K, ST25TV64K or ST25TV512, ST25TV02K ?

Best regards.

Luke_abc · ‎2024-01-26

It is for ST25TV16K and ST25TV64K. Is it possible for these series ?

JL. Lebon · ‎2024-01-26

Hello,

For the ST25TV16K and ST25TV64K, it is not possible to lock more blocks than block 0 and 1.
Nevertheless, it is possible to do what you want to do, which is locking all the blocks permanently using the password mechanism.

If you look at the RFA1SS, RFA2SS etc. and in particular at fields PWD_CTRL_Ax, you can see that value 00b in this filed means: "RF user security session can't be opened by a password". If you combine this with field RW_PROTECTION_Ax=01b (write protection), it means that the corresponding memory area will be protected against write and there will be no way to unprotect it using a password. So, the write protection is permanent, which looks like what you are willing to do.

Off course, someone who knows the configuration password can still change those settings. If you don't want this to happen, you can lock the configuration (LOCK_CFG configuration byte).

Best regards.

Luke_abc · ‎2024-01-26

Hi @JL. Lebon ,

Than you for your reply. Is it possole to kill the tag if LOCK_CFG =1 ?

JL. Lebon · ‎2024-01-26

Hello,

No it is no more possible once LOCK_CFG=1.

Best regards.