SPRACS4 June   2020 TMS320F2800132 , TMS320F2800133 , TMS320F2800135 , TMS320F2800137 , TMS320F2800152-Q1 , TMS320F2800153-Q1 , TMS320F2800154-Q1 , TMS320F2800155 , TMS320F2800155-Q1 , TMS320F2800156-Q1 , TMS320F2800157 , TMS320F2800157-Q1 , TMS320F28384D , TMS320F28384D-Q1 , TMS320F28384S , TMS320F28384S-Q1 , TMS320F28386D , TMS320F28386D-Q1 , TMS320F28386S , TMS320F28386S-Q1 , TMS320F28388D , TMS320F28388S , TMS320F28P650DH , TMS320F28P650DK , TMS320F28P650SH , TMS320F28P650SK , TMS320F28P659DH-Q1 , TMS320F28P659DK-Q1 , TMS320F28P659SH-Q1

 

  1.   Enhancing Device Security by Using JTAGLOCK Feature
    1.     Trademarks
    2. 1 Security Feature on C2000 Device
    3. 2 JTAGLOCK Feature
      1. 2.1 Z1OTP_JLM_ENABLE
      2. 2.2 JTAG Password
        1. 2.2.1 Z1OTP_JTAGPSWDHx
        2. 2.2.2 Z1OTP_JTAGPSWDLx
    4. 3 Enabling JTAGLOCK
      1. 3.1 CCS Flash Plug-in GUI
      2. 3.2 Security Configuration Embedded in .out File
    5. 4 Disabling JTAGLOCK
      1. 4.1 Target Configuration (.ccxml) File
    6. 5 Permanent JTAGLOCK
    7. 6 References

2.2.2 Z1OTP_JTAGPSWDLx

JTAGPSWDLx (JTAGPSWDL0 and JTAGPSWDL1) is the lower half of 128-bit JTAG password located in each of the Zone Select Block (ZSB) of Zone1 USER OTP of CPU1. You can change these 64-bit values by selecting a new Zone Select Block (ZSB), if needed. For detailed information about the Zone Select Block (ZSB), see the Dual Code Security Module section in device-specific Technical Reference Manual.

Table 4. Z1OTP_JTAGPSWDLx

JTAGPSWDLx USER OTP Address
JTAGPSWDL0 Zone_Select_Block address + 0x1C
JTAGPSWDL1 Zone_Select_Block address + 0x1E

Basically, you can initially choose a 128-bit password to protect the JTAG interface, but only the lower 64-bit can be modified later and the upper 64-bit remains same.