MIPS-Lite Debugging Utilities

For this assignment we have added several debugging utilities to the verilog model. These are commands that can be typed at the verilog prompt to enable features or print information to the screen. The following utilities are provided:

Name 	        Description
--------- 	-------------------------------------------------------
`help 	        Help. Prints this list of utility descriptions
`por 	        Power-On Reset
`ss 	        Toggles single step
`it 	        Toggles instruction stream trace
`waves 	        Start the waves display
`regs 	        Start the register display
`output 	Dumps memory to memory.core
`rfd 	        Dumps the register file
`break = #;	Sets a breakpoint in the code
`start = #;	Sets the start address for `dismem and `dumpmem
`num = #; 	Sets the number of words to dump for `dismem and `dumpmem
`dismem 	Disassembles `num' words starting at address `start'
`dumpmem 	Dumps `num' words starting at address `start'

Some of the more useful ways to use these commands:

When you want to rerun a program type `por at the verilog command line. This will reinitialize memory and restart the program.
To single step through cycles, type `ss. To turn single stepping off, type `ss again.
`it toggles the instruction trace on and off similarly to the `ss command.
The `waves, `regs, and `output perform the same function as the +waves, +regs, and +output options except that they may be called after Verilog is already running.
With the `break command, you can set breakpoints in the code. That is, if you want the program to stop when it reaches the instruction at 0x100, then type `break = 'h100; at the verilog prompt before running the program.
With the last four commands, you can also dump any portion of memory. Say for example you wanted to dump the array in bubble which starts at location 0x50. You would type the following sequence:
```
`start = 'h50; 
`num = 6; 
`dumpmem;
```
This will dump six words starting at location 0x50. If you use the 'dismem routine, it will also disassemble memory.

If you ever forget one of the routines, simply type `help at the Verilog command line.