NVIS 5586A, Learning Material

Page: 78 / 191

Nvis 5586A
Nvis Technologies Pvt. Ltd. 78
Practical Examples of Subprogram:
Note:
Programs in Assembly language directly compile on Trainer Assembler while writing
program in Assembly language in Trainer do not add prefix Zero (0) or any postfix like H as
shown in figure and use address of label names in place of Label name in trainer.
Example 1:
Input alphabetical key, and display at LCD.
Address Opcode Mnemonic Comment
0:0400 B0 01 MOV AL, 01 CLEAR DISPLAY COMMANDS TO BE
STORED IN AL
0:0402 9A 44 F0 00 F0 CALL F000:F044 CALLING INSTRUCTION IS INPUT INTO
LCD RAM
0:0407 B0 0D MOV AL, 0D COMMAND THAT DISPLAY ON/OFF IS
STORED IN AL0D= 0000 1101 LETTER
BLINKING CURSOR OFF DISPLAY ON
DISPLAY ON/OFF ORDER
0:0409 9A 44 F0 00 F0 CALL F000:F044 CALL FOR WRITE-IN INSTRUCTION
SUBPROGRAM
0:040E 9A 50 F0 00 F0 CALL F000:F050 CALL FOR THE READ KEY-IN
0:0413 9A 58 F0 00 F0 CALL F000:F058 CALL THE ALPHABETICAL KEY CODE
AND TRANSFER INTO THE SUBPROGRAM
0:0418 72 F4 JB 040E IGNORE THE ALPHABETICAL KEY-IN,
RETURN
TO ORIGINAL KEY-IN;
OTHERWISE EXECUTE THE NEXT
INSTRUCTION.
0:041A 9A 48 F0 00 F0 CALL F000:F048 KEY-IN CODE ENTER INTO LCD MODULAR
0:041F E9 EC FF JMP 040E
0:0422 F4 HLT
Program input starts executing from 0400; the first word blinking can be seen at this time,
they can be input again in order to be displayed on LCD. 21st to 41st word will exceed the
first line display boundary; therefore they are stored in LCD modular but will not be shown.
The 41st word will be the first letter on the second line. Similarly, 61st to 80th word will not
be shown.