lcd.doc

一个C style Assembler的source code

               T h e   I O   K e y p a d / L C D   D e m o

(0) OVERVIEW
   This demo is meant to be used with the io.lib software.  For me, its
primary function has been to verify and test the keypad and LCD hardware, and
the associated circuitry.

(1) COMMAND SUMMARY
   To run this demo, you will either need (1) compatible hardware to use with
io.lib or (2) to write yout own emulator for the io.lib routines.  The emulator
could be, for instance, a set of routines that communicate with a client over
an RS-232 line.
   You will need to locate the keys that correspond to the numeric values 0 to
15 before using this demo, since all the commands are executed from the keypad.

                      IO Demo Command Summary
            Command                   Function
            0 NN                      cputs(NN)
            1                         clear
            2                         home
            3 N                       set_cursor(N)
            4                         cursor_left
            5                         cursor_right
            6                         shift_left
            7                         shift_right
            8 RC                      locate(Row, Col)
            9                         scr_init
            10                        cputs("This is a test")
            11                        save_cursor
            12                        restore_cursor

The numerical inputs, NN, N and RC are keyed in from the keypad following
the command, one hexadecimal digit at a time.  The keys 0 to 15 are mapped
onto the hexadecimal digits 0-9, a-f respectively.  The numbers NN and RC
are two hexadecimal digits, and N is one.
   Because of the constraints on the command format,  it will not be possible
to "locate" past column 15 using the command 8.  The first hex digit (R) is
the row where the cursor is to be located, and the second is the cursor's
new column, which cannot be larger than 16.
    The commands listed above are all described in IO.doc.