README for Download Library
---------------------------

The files in this directory support a Keil C project 'download.prj' which
builds a library (download.lib) to implement software download.

They are:

download.c - 'main' module that provides a clean interface to user code and sets
              up an RTX-51 task to run software download.
              
datagram.c - link layer code, sets up a reliable communications channel with the PC.

serial.c   - physical layer code, manages the UART chip.  Edited version of a Keil 
             Software example program

decrypt.c  - applications layer code, implements DES CBC decryption and MAC checking.

install.c  - manages the Flash EPROM.  Makes sure that only one 'half' of the Flash
             contains executable software.

nvdata.c   - low-level access routines for the Flash ROM.

DES.c      - implements single and triple DES decryption functions.

ISRS.c     - interrupt routine stub to reserve the interrupt used by the ICE debug functions


             

             





