ISP is the acronym of In-System Programming, and ICP is the acronym of In-Circuit Programming. Both these two programming methods make it possible that the user can update the application code under the software control without removing the mounted MCU chip from the actual end product. The tool ¨Megawin 8051 ISP-ICP Programmer, see the follow picture, integrates these two functions into a USB stick. That is it can function as an ISP Programmer and an ICP Programmer. In addition, because the programming data to be programmed to the target can be saved in the programmer≈s non-volatile storage, this programmer is able to work stand-alone without host (PC) intervention. This feature is especially useful in field without a PC.