Using IC

IC is started from the Unix shell by typing ic at the prompt. Some Unix systems (in particular, MIT Athena DECstations) have an unrelated application named ic. If this application is first in the execution path, it will be invoked rather than the IC compiler. This situation may be remedied by reordering the execution path to include the path to the IC compiler first, or by using the program name icc, which will also invoke IC.

IC can be started with the name (or names) of a C file to compile.

When running and attached to a 6811 system, C expressions, function calls, and IC commands may be typed at the "C>" prompt.

All C expressions must be ended with a semicolon. For example, to evaluate the arithmetic expression 1 + 2, type the following:

C> 1 + 2;

When this expression is typed, it is compiled by the console computer and then downloaded to the 6811 system for evaluation. The 6811 then evaluates the compiled form and returns the result, which is printed on the console computer's screen.

To evaluate a series of expressions, create a C block by beginning with an open curly brace { and ending with a close curly brace }. The following example creates a local variable i and prints 10 (the sum of i + 7) to the 6811's LCD screen:

C>{int i=3; printf("%d", i+7);}

• IC Commands
• Line Editing
• The main() Function

IC Commands

IC responds to the following commands:

load filename

Load file. The command load filename compiles and loads the named file. The board must be attached for this to work. IC looks first in the local directory and then in the IC library path for files. Several files may be loaded into IC at once, allowing programs to be defined in multiple files.

unload filename

Unload file. The command unload filename unloads the named file, and re-downloads remaining files.

list files

The command list files displays the names of all files presently loaded into IC.

list globals

The command list globals displays the names of all currently defined global variables.

list functions

The command list functions displays the names of presently defined C functions.

list defines

The command list defines displays the names and values of all currently defined preprocessor macros.

kill_all

Kill all processes. The command kill_all kills all currently running processes.

ps

Print process status. The command ps prints the status of currently running processes.

help

Help. The command help displays a help screen of IC commands.

quit

Quit. The command quit exits IC. ^c can also be used.

Line Editing

IC has a built-in line editor and command history, allowing editing and re-use of previously typed statements and commands. The mnemonics for these functions are based on standard Emacs control key assignments.

To scan forward and backward in the command history, type ^p or uparrow for backward, and ^N or downarrow for forward.

An earlier line in the command history can be retrieved by typing the exclamation point followed by the first few characters of the line to retrieve, and then the space bar. For example, if you had previously typed the command C> load foo.c, then typing C>!lo followed by a space would retrieve the line C> load foo.

The following are the keystroke mappings understood by IC.

IC does parenthesis-balance-highlighting as expressions are typed.

The main() Function

After functions have been downloaded to the board, they can be invoked from the IC prompt. If one of the functions is named main(), it will automatically be run when the board is reset.

To reset the board without running the main() function (for instance, when hooking the board back to the computer), hold down the board's ESCAPE button while pressing reset. The board will reset without running main().