Summary

While you could do all of your development using an external programmer (and many have), the development process is much more efficient if you can download new code directly to the target and update the flash memory using its in-circuit programming capability. Thus, getting some kind of file transfer working should be one of your top priorities. MicroMonitor supplies support for the two most universal file transfer protocols: Xmodem and TFTP.

Typically, when bringing up a new installation of MicroMonitor, I begin by getting the serial port and Xmodem working. Even if the board includes an Ethernet interface, I often use the serial port (if available) for the initial development efforts. The Xmodem code is much smaller and simpler, and the Mtrace feature makes it easier to debug the link. Moreover, until recently at least, host-based development tools are more apt to expect a serial link to the target than a network link. Later, when I have richer debugging support functioning, I might install the TFTP support and switch to TFTP for file download.

Both protocols give you good interconnectivity. While the Xmodem implementation deliberately excludes the error handling normal in a modem-oriented implementation, it is still a compatible implementation. So long as you use it over a direct, error-free line, it should work with most Xmodem packages. The TFTP implementation is much larger, but it complies fully with the relevant request for comments (RFC). Both options include features that make them useful in the early stages of development, even when TFS isnt present or isnt fully operational.