Due: March 8, 2021 11:30pm
Objective
To learn how to use arithmetic instructions and write basic system I/O subroutines. Learn user interface through a serial port.
Instruction
- Write a user-friendly system program for the following commands:
S: Show the contents of memory location
W: Write the data byte to memory location
QUIT: Quit the main program, run ‘Type writer’ program. - Command S: This command shows the contents of memory location specified by the address in hexadecimal number followed by the ‘S’ character. For example, if the data $6A is stored in memory location $3000, a user types in the first line ending with Enter/Return key and the following should be displayed on the HyperTerminal connected to the HCS12 board:
>S$3000
$3000 = $6A 106
>The data $6A is printed in both hexadecimal and decimal number format. The character ‘>’ is the prompt for this program.
- Command W: this command writes data into the memory location specified by the address in hexadecimal followed by the ‘W’ character. The data to be written to the memory location is followed by a space and it can be specified by hexadecimal ‘$’ or just decimal number. For example, if one wants to store the data $6A in memory location $3001, a user types in the first line ending with Enter/Return key and the following should be displayed on the HyperTerminal connected to the HCS12 board:
>W$3001 106
$3001 = $6A 106
>Or
>W$3001 $6A
$3001 = $6A 106
>As a result, the data $6A is stored in the memory location $3001 and it is shown with the ‘S’ command. The ‘W’ command accepts both ‘106’ or ‘$6A’ as an 8 bit number.
- For HCS12 chip, assume memory address is a 16 bit number and each memory location hold an 8 bit data.
- Design the program to start at $3100 and data to start at $3000.
- Make your program user-friendly and fool proofed. Print detail guide on the terminal screen so that users will properly use your program. Once your program is running, everything must be self-explanatory to user at the Hyper Terminal.
- For this homework, you must do error checking to see if correct input is entered by a user. And give correct command usage example if invalid command was entered. Your program must NOT crash or hang if a user enters wrong input.
- The HyperTerminal display should look something like the following:go 3100 Welcome to the Simple Memory Access Program! Enter one of the following commands (examples shown below) and hit ‘Enter’. >S$3000 ;to see the memory content at $3000 > $3000 = $6A 106 > >W$3001 $6A ;to write $6A to memory location $3001 > $3000 = $6A 106 > >W$3001 106 ;to write $6A to memory location $3001 > $3000 = $6A 106 > QUIT ;to the Simple Memory Access Program Type writing now: >S$30G0 > invalid input, address > >S$30123 > invalid input, address > >S345678 > invalid input, address > >W$3001 $6AB > invalid input, data > >W$3001 300 > invalid input, data > >W$3001 > invalid input, data > >W$3001 -106 > invalid input, data > >W$3 $0F > $0003 = $0F 15 > >W$300 $9 > $0300 = $09 9 > >W$4000 12 > $4000 = $0C 12 > >W$0001 005 > $0001 = $05 5 >
- You may want to first draw the Flow Chart of the above algorithm.
- Be sure to put much comments so that grader and others can clearly and quickly understand your program. Comments are very important in assembly language programs.
- You may want to see and check the Sample Grading Sheet for this homework.
- Copy your ‘main.asm’ file to ‘cmpen472hw6_YourLastName.asm’. For example, mine will be ‘cmpen472hw6_choi.asm’ Then turn-in your .asm file (do NOT ZIP your file).
- Turn-in your project source code file through Penn State CANVAS. Upload your source code file into the CANVAS Assignment’s Homework submission. Be sure to select CMPEN 472 class and correct Homework number, and with correct file name.
Congratulations on your sixth CMPEN 472 homework completion!
Here is a link for the codewarrior idle install https://drive.google.com/file/d/19HVtjjhX8aJEh2oDa…
