UART Wildcard User Guide

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Using the Driver Code with Forth

After loading the install.txt file and typing COLD, use the terminal to send the "library.4th" file to the Mosaic Controller. Library.4th sets up a reasonable memory map and then defines the constants, structures, and name headers used by the UART Wildcard kernel extension. Library.4th leaves the memory map in the download map.

After library.4th has been loaded, the board is ready to receive your high level source code files. Be sure that your software doesn't initialize the memory management variables DP, VP, or NP, as this could cause memory conflicts. If you wish to change the memory map, edit the memory map commands at the top of the library.4th file itself. The definitions in library.4th share memory with your Forth code, and are therefore vulnerable to corruption due to a crash while testing. If you have problems after reloading your code, try typing COLD, and reload everything starting with library.4th. It is very unlikely that the kernel extension runtime code itself (install.txt) can become corrupted since it is stored in flash on a page that is not typically accessed by code downloads.

We recommend that your source code file begin with the sequence:

This moves all pre-loaded flash contents to RAM if the Mosaic Controller is in the standard (flash-based) memory map, and then establishes the download (RAM-based) memory map. At the end of this sequence the Mosaic Controller is in the download map, ready to receive additional code.

We recommend that your source code file end with the sequence:

This copies all loaded code from RAM to flash, and sets up the standard (flash-based) memory map with code located in pages 4, 5 and 6. The SAVE command means that you can often recover from a crash and continue working by typing RESTORE as long as flash pages 4, 5 and 6 haven't been rewritten with any bad data.

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