How to judge whether the IC has been burned? Basic principles of chip programming

Date：2021-09-13 11:14:00Views：4326

Chip burning is an important link in the production of electronic products. The efficiency is an important aspect of customer concern. How to judge whether the IC has been burned? The burning efficiency is inseparable from the burning speed of the chip. The principle of chip programming is explained.

The principle of single chip microcomputer burning is that a burning program already exists in single chip microcomputer. When starting the single chip microcomputer, first run the program to judge the port state. If the state of "to burn ROM" exists, read the data from a port (serial port, SPI, etc.) and then write it into the ROM of the single chip microcomputer. If there is no "to burn ROM" status, go to the user's program and start execution.

There are three ways to burn the principle of single chip microcomputer:

1. The single-chip microcomputer is regarded as a ROM chip, which is the case in the early single-chip microcomputer. When the MCU is programmed on the general programming, it is like the process of writing programs in rom such as 28c256.

2. Like AT89S52 or AVR single chip microcomputer, there is SPI interface on the single chip microcomputer. At this time, the program is burned into the single chip microcomputer with a special download line. At this time, the difference is that the CPU of the single chip microcomputer can not only execute the instructions of the single chip microcomputer itself, but also execute special instructions for ROM operation, such as ROM erase, burn and check instructions. When programming ROM, the download line first transmits these instructions to the CPU for execution (erasing ROM, reading data, Burning ROM, and verifying ROM), so as to complete the burning of the ROM of the single chip microcomputer.

3. Boot program, that is, a burning program already exists in the single chip microcomputer. When starting the single chip microcomputer, first run the program to judge the port state. If the state of "to burn ROM" exists, read the data from a port (serial port, SPI, etc.) and then write it into the ROM of the single chip microcomputer. If there is no "to burn ROM" status, go to the user's program and start execution.

To understand this principle, we need to know several knowledge points:

Single chip microcomputer integrates a computer system into a chip. Equivalent to a microcomputer, compared with a computer, a single chip microcomputer only lacks I / O equipment.

Click To summarize the principle of slice burning:

ICP: use SWD interface for burning, such as j-link burner and j-flash software.

ISP: use bootload and peripheral UART / USB interfaces for burning.

IAP: the method of realizing online electrical erasure and programming by the software itself without using any tools. The program is usually divided into two parts, boot program and application program.

It can be understood metaphorically: the single chip microcomputer is the main board of the computer, and the program we write is the operating system. The main board is loaded with the basic program to guide the operating system, and the download program is to install the system for the computer.

How to judge whether the IC has been burned. Whether the IC has been burned, first of all, from the internal structure, check whether the IC has been burned through the burner.

First, through the blank check, if the burned IC has not been cleared by the customer, some data will remain in it. At this time, we can see whether the IC has been burned.

Second, through appearance inspection, whether the IC has been soldered with tin, customers sometimes make some marking points, that is, mark some color marks to identify whether the IC has been burned from the appearance.

Third, check the production cycle of IC and the time period in which it is produced. Generally speaking, the production cycle of IC is calculated by week. We can check the year or week marked on the IC.

When checking the IC, if the customer has cleared it and its appearance is very new, it is difficult to determine. If the appearance of the IC is good and blank, as long as the function of the IC is good, you don't have to care too much. In order to distinguish different versions of IC, general customers will dot it on the IC.

Generally speaking, the goods from the original factory have not been burned, and the inside is blank. You can judge whether this IC has been burned by checking whether it is blank. At the appearance level, check whether there are some marking points and whether the footnote has been soldered with tin to identify whether the IC has been burned.