To disable the JTAG access on a device to avoid
any debug access, use the JTAGLOCK feature on this
device. Follow a two step process to enable the
JTAGLOCK feature (both steps can be performed at the
same time):
- Program the JTAG passwords. This device has a
128-bit JTAG password that needs to be programmed
in Z1 USER OTP. JTAG passwords are split into two
parts, JTAGPSWDH and JTAGPSWDL. JTAGPSWDH is part
of Z1 USER OTP header and JTAGPSWDL is part of Z1
Zone Select Block (ZSB). What this means is
program JTAGPSWDH once and change the JTAGPSWDL
multiple times, if needed. The Code Composer
Studio™ IDE has an integrated tool that you use to
unlock the JTAGLOCK on the device.
- After programming the JTAG passwords, enable the
JTAGLOCK module (JLM) by programming bit [3:0] of
Z1OTP_JLM_ENABLE with any value other than 0xF. It
is recommended to program all four bits with a
value 0x0.