Chip and method capable of authenticating off-chip debug firmware program and debug user

A chip capable of authenticating an off-chip debug firmware program and a debug user, comprising:

• a non-volatile memory storing a secure boot firmware, a secure boot public key and a debugging function default value;
• a debugging function control component comprising at least one debugging function and a register configured to store at least one debugging function state value, wherein an initial value of the debugging function state value stored by the register is the debugging function default value;
• a volatile memory;
• and
• an at least one processor configured to run the secure boot firmware for verifying a signed program loaded from an external storage device according to the secure boot public key and running a debug firmware program of the signed program after the signed program is successfully verified to verify whether the debug user of an external debugging tool connected to the chip is a valid debug user by a debug user authentication algorithm of the signed program, wherein the debugging function is provided to be used by the valid debug user.