What to choose: Online or Offline Programming?


Almost all intelligent electronic products have programmable devices installed such as NOR, NAND FLASH, eMMC, microcontroller, EEPROM, CPLD etc. Therefore, IC programmer becomes production necessary equipment for any electronic manufacturing company.

Off-line Programming: This production process is common, the chip will first go through the programming process, which can be manually or automatically programmed, then go to SMT placement. This production process is called Off-Line Programming (or parallel programming), it has been widely adopted and well known.

On-line Programming: Another production process, which we call the online programming (ISP, the In-the System Programming, the In-Circuit Programming ) , which is commonly used in R & D and sometimes in mass production.

How to choose the best programming solution from above two methods?

What are the advantages and disadvantages of each? This is a problem faced by many companies and engineers. This article will make this simple analysis and make it easier for you to choose best solution for your application.

Off-line Programming On-line Programming (ISP)
Versatility Suitable for all types of chips Applicable only in two cases
1) Chip supports ISP
2) Circuit board is designed for ISP with proper pin access.
Productivity 1) Programming speed Programming speed is usually higher in case of offline programming as we have easy access to parallel interface of chips and speed is faster with parallel data transmission.
2 ) Concurrent Programming SuperBOT-3 is equipped with 32 sockets so concurrent programming of 32 chips is easily possible in most cases.
3) Throughput Automatic programmers can operate at throughput of 1600 UPH (Units per hour)
4) Other expenses Programming is an independent process, and will not have any effect on testing cost.
1) Programming speed. Programming speed is slower in case of serial programming as compared to parallel programming done by automated/parallel programmers as the data bits are transferred sequentially.
2) Concurrent programming Concurrent programming is decided by the number of channels each ISP programmer supports and size of PCB panel is also a limiting factor. With smaller size PCB, larger panel can be supported. Superpro IS03 can support a panel of 16 PCBs.
3) Throughput: It is not as high as automated programmers
4) Other Expenses: If programming is done on an ICT then extra time is needed on the tester which may involve additional operating cost,
Investment Initial Investment is higher and user has to consider operating costs for the socket adapters. The cost is easily recovered if chip programming requirement is very high. Initial investment is lower and customer should consider cost for pogo pin replacement along with cost of manual operator.
Rework difficulty For various reasons, such as the incorrect data file, firmware upgrades, and other factors sometimes it is necessary to reprogram the chips. In case of offline programming, reworking is needed to desolder and solder the chip. No rework needed for data file changes and field upgrades,
Flexibility Changeover time from one chip to a different chip is couple of minutes in case of automated programmer. User needs to install correct socket adapter and ready to go after loading project file. New programming algorithm development and testing might be involved when chip part number or PCB changes. Also there will be a need of designing new test fixture for different PCBs.
Reliability of product and quality During programming, because the chip has to go in and out of the socket and feeder equipment, careless operation of automatic programming may result in chip pins deformation, resulting in degradation of soldering quality. So some of the aerospace, defense, automotive electronics, medical electronics and other high reliability requirement companies don't prefer offline programming. Programming is done after surface mounting so no such risks are involved,


To summarize, what kind of programming solution customer chooses depends on various factors such as type of chip , programming file size requirements, cost estimates, the nature of products, reliability requirements. User needs to make a comprehensive analysis of their needs in order to make the best choice.

Xeltek is a global, high-tech company, leader in a wide range of professional systems dedicated to online / offline IC programming. Having been the world's leading provider of manual and automated device programming systems for Flash, Microcontroller and Logic devices since 1991, our continuous focus on quality, support and programming speed helps our customers achieve excellence in production and product quality.

Offline Programmer Recommendation

    • SuperBOT 2 16 socket automated programmers
    • SuperBOT 3 32 Socket automated programmers
    • SuperBOT 4 Desktop Automated Programmer with Tray IO.


Online Programmer Recommendation

    • Superpro / IS01 -channel ISP programmer
    • Superpro / IS03 16 channels ISP Programmer
    • Superpro / XPS01 ISP workstation


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