36.7.32 Secure PIO Tamper Freeze Register

Name: S_PIO_TPFR
Offset: 0x15D0
Reset: 0x00000000
Property: Read/Write

Bit 3130292827262524 
 FRZKEY[23:16] 
Access WWWWWWWW 
Reset 00000000 
Bit 2322212019181716 
 FRZKEY[15:8] 
Access WWWWWWWW 
Reset 00000000 
Bit 15141312111098 
 FRZKEY[7:0] 
Access WWWWWWWW 
Reset 00000000 
Bit 76543210 
        TAMPFRZ 
Access R/W 
Reset 0 

Bits 31:8 – FRZKEY[23:0] Freeze Key

ValueNameDescription
0x545046 PASSWD Writing any other value in this field aborts the write operation of the TAMPFRZ bit.

Bit 0 – TAMPFRZ Freeze on Tamper Event

On tamper detection, Secure I/O lines with TAMPEN bit at 1 will be forced as GPIO inputs with pull-up.

Only a hardware reset can reset the TAMPFRZ bit.

ValueDescription
0 No effect.
1 Enables to freeze Secure I/O lines on tamper event detection if FRZKEY corresponds to 0x545046 (“TPF” in ASCII).