Method for protecting chip internal information security based on JTAG port control

Abstract

This invention provides a method for protecting information safety inside chips based on the JTAG port control, in which, said chip includes: a non-volatile medium used in storing JTAG lock on instruction, a JTAG locking controller used in controlling the border scan chain of the JTAG port and its registor, and the method includes: when the chip is turned on, the JTAG locking controller detects the JTAG lock-on instruction and judging if the instruction has be written into the JTAG instruction storage unit, the controller cuts off the border scan chain to stop the work of the port registor andcontrols a program guide of the chip to let it refuse leading codes from outside to inside.

Description

technical field [0001] The invention belongs to the technical field of a system chip (SOC), and in particular relates to a method for protecting chip internal information security based on JTAG port control. Background technique [0002] With the improvement of the design level of large-scale integrated circuits, it is the general trend to integrate a variety of ICs with different processes into a single chip to build a SOC (system on chip), and SOC-based products are becoming more and more popular in the market. SOC can make the whole machine product composed of discrete IC devices lower in cost, lower in power consumption, and higher in reliability. [0003] JTAG (Joint Test Action Group, Joint Test Action Group) is an international standard test protocol (IEEE 1149.1 compatible), mainly used for chip internal testing (Boundary Scan [0004] However, with the improvement of chip integration, the contradiction between openness and security is becoming more and more promine...

AI Technical Summary

Problems solved by technology

[0006] 1. Lost boundary scan function;

[0007] 2. Due to non-compliance with IEEE1149.1 specification, the support of third-party tools is lost;

[0008] 3. Unable to simulate and debug in real time, the development of embedded software is difficult and the cycle is long;

[0009] 4. Cannot effectively block the attack of off-chip software;

The disadvantage of this method is that the fusing process is irreversible, once the fusing, the chip can no longer recover

This method is suitable for simple and cheap microcontrollers, but not for complex and expensive high-end processors or SOCs

[0011] In the prior art, there is no information security protection method that can not only allow the chip to enjoy the convenience brought by the JTAG interface but also have sufficient security.

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