Method and system for entering programming mode based on two-way handshake

Abstract

The invention relates to a method and system for entering a programming mode based on two-way handshake. The method comprises the steps that: (1) a programming tool changes an SCL signal and resets achip, (2) after a chip detects the change of the SCL signal, the preparation of programming is started and an SDA signal is changed, (3) after the programming tool detects the change of the SDA signal, the programming is prepared, and the SCL signal is changed again after the programming tool completes preparation, (4) after the chip detects the change of the SCL signal again, the preparation of programming is completed, and the SDA signal is changed again, (5) after the programming tool detects the change of the SDA signal again and the programming tool enters the programming mode, (6) a programming operation is carried out, and (7) the chip enters a normal operation state. The method and the system are used, the separate package of test pins is not needed, the packaging cost is reduced,the application of a high-voltage signal is not needed, the power crosstalk is reduced, an external reset pin is not needed, and the operation of personnel is simplified.

Description

technical field [0001] The present invention relates to the field of microelectronics technology, in particular to the field of FLASH programming technology, and specifically refers to a method and system for entering into a programming mode based on a two-way handshake. Background technique [0002] Chips with FLASH (MTP (multiple time programmable, multiple times programmable)) in the prior art enter the programming mode, and there are three methods: [0003] 1. Use a single test pin, a high level indicates that the FLASH needs to be programmed, and a low level indicates normal function; [0004] 2. Apply high voltage to a chip pin to enter the FLASH programming mode; [0005] 3. During the reset period, enter the test command to enter the FLASH programming mode; [0006] There are certain drawbacks in the above three methods: [0007] 1. A single pin is required. Sometimes the chip pins are not enough, and there is no extra pin position to package this test pin. It is ...

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Problems solved by technology

[0007] 1. A single pin is required. Sometimes the chip pins are not enough, and there is no extra pin position to package this test pin. It is uneconomical to increase the number of package pins specifically for this pin. ;

[0008] 2. The way of adding high voltage to the pins of the chip can easily cause crosstalk between the high voltage of the high voltage pin and the normal voltage of the circuit;

[0009] 3. Instructions are issued during the reset period, and the digital voltage is stable after power-on. Depending on the peripheral load, the time required is different. Generally, this order of magnitude is milliseconds. Some chips require a relatively early reset end time due to multi-chip cooperative work. , such as within 10ms, then the time for external commands is only a short period of time from the stabilization of the digital voltage to the end of the reset. This is a very troublesome thing for external programming devices, and programming personnel often appear to enter Although this method can control the external reset pin to prolong the reset time to avoid the phenomenon that the programming command is unsuccessful, some customers currently suspend the external reset pin on the program board directly in order to save costs. Using this method, the reset pin is suspended in the air, resulting in When the reset pin cannot be used for reset, enter commands and perform FLASH programming, which will increase user costs and be inconvenient to use

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