Create modular code and interface with unfamiliar modularized code

The Task

In this project, you will be writing a program that converts a string to an integer (similar to Java’s

Integer.parseInt() method or Python’s int() function). You program will receive ASCII strings from the UART, one

character at a time. It should convert each string of characters into an integer value that is passed to a provided

print function. Strings will be terminated using a semicolon (;) character and will contain one or more characters

in addition to the semicolon. Your program should be able to handle multiple strings concatenated together and

treat each string ending with a ‘;’ as a separate input. When processing strings, it should detect any invalid

characters within a string. Invalid characters are any characters other than ‘0’ through ‘9’ and ‘;’. If an invalid

character is detected then the rest of the string (i.e. all characters leading up to and including the next ‘;’) should

be received by the UART, but ignored. Your program should then use the print function to output an error

message and then continue processing the next string as a new string.

Print Function

A skeleton PLP project file is available to download on Blackboard. The PLP project includes a second ASM file

titled, project3_print.asm. This ASM file contains the print function used in this project. PLPTool concatenates all

ASM files within a PLP project into a single location in memory (unless additional .org statements have been

added to specify different location for code). No changes to project3_print.asm should be made.

When called, the print function will send the value currently in register $a0 over the UART to the PLPTool

simulated UART device. Register $a1 is used as an invalid character flag for the print function. If $a1 register

contains a non-zero value, the print function will display an invalid character message instead of the value in

register $a0. The print function is called using the following instruction:

call project3_print

To use the print function, your PLP program needs to initialize the stack pointer ($sp) before performing the

function call (or any other operations involving the stack pointer). For this reason, the skeleton project file

includes an initialization that sets the stack pointer to 0x10fffffc (the last address of RAM). This initialization

only needs to be done once at the start of the program.

Deliverables: 1. Take the Project 3 Pre Quiz on Blackboard (3 points) 2. Submit your program on Blackboard with the format: lastname_project3.plp (25 points)

Note: Please do not zip the project file or include any additional files in your submission 3. Take the Project 3 Post Quiz on Blackboard