Instruction memory verilog code

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Designing a CPU in VHDL, Part 3: Instruction Set Architecture, Decoder, RAM

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instruction memory verilog code

Our assignment is to build a rudimentary single-cycle CPU in Verilog, but I'm not getting even more fundamental modules of it correct. For instance, to test the Instruction Memory module, we've been given a text file "hw3Test. When I run a testbench, I see that the only instructions that get into memory are the second, third, and fourth lines. Here's the IM module:. I'm also not sure I'm even getting the PC-to-IM module correct, because aside from the initialized values, everything but the rst and clk signals show no valid values.

Can anyone point out where I'm going wrong? This block will only activate on positive clock edges. However, you make reset high while the clock is paused so no reset will happen. Learn more. Asked 6 years, 10 months ago. Active 6 years, 10 months ago. Viewed 3k times. PCin PCin. Lee Wang Lee Wang 71 1 1 silver badge 4 4 bronze badges. Active Oldest Votes.

Basic digital logic components in Verilog HDL

Here are a few things that look suspect. Problem 1 It is normally good to use non-blocking assignments in blocks intended to infer registers. Peter de Rivaz Peter de Rivaz Sign up or log in Sign up using Google. Sign up using Facebook. Sign up using Email and Password. Post as a guest Name. Email Required, but never shown. The Overflow Blog. Podcast Cryptocurrency-Based Life Forms. Q2 Community Roadmap.Yes, you are right.

Just an example, modify it to whatever you want. That's only for debugging in simulation. You can commented it out in the top level code like John E if you don't want to see it in simulation. Basic digital logic components in Verilog HDL. In this Verilog projectbasic blocks in digital logic design such as D-Flip-Flop, adders, ALU, registers, memory, multiplexers, decoders, counters, etc.

What is an FPGA? Verilog code for FIFO memory 3. Verilog code for bit single-cycle MIPS processor 4. Verilog code for basic logic components in digital circuits 6. Verilog code for bit Unsigned Divider 7. Verilog code for Fixed-Point Matrix Multiplication 8. Verilog code for Carry-Look-Ahead Multiplier Verilog code for a Microcontroller Verilog code for 4x4 Multiplier Verilog code for Car Parking System Verilog code for Traffic Light Controller Verilog code for comparator design Verilog code for D Flip Flop Verilog code for Full Adder Verilog code for counter with testbench Verilog code for button debouncing on FPGA N-bit Adder Design in Verilog.

How to generate a clock enable signal in Verilog Verilog code for PWM Generator Verilog coding vs Software Programming. Unknown March 22, at AM. Unknown April 2, at AM. Admin June 28, at PM.May i check with you what type of stimulus do i have to include in the test bench codes.

I ran the whole program with the testbench for ns but the register values are 0 or x. Double check your instruction memory. All instructions here are fully verified. You can check instruction by instruction and see register files, data memory to verify.

Verilog HDL Basics

Ok thanks for your advice. How do i implement a pipeline structure into a mips processor? Do i just implement a register in between individual stages? If so where do i implement them.

I tried that but the end output just outputs 'z's??? I guess I dont know what is supposed to be happening here. Please post verilog codes for 32 bit pipelined risc processor with data path and control unit explanation.

That's only for debugging in simulation. You can commented it out in the top level code if you don't want to see it in simulation. I read that mips is risk based processor!

Isn't it a 16 bits per word memory? Just a memory word alignments a MIPS data access unit. Thanks for your question. It is a bit CPU, so 2 byte per word.

instruction memory verilog code

The PC and the Offset address is increased by 2. Verilog code for bit single cycle MIPS processor. MIPS is an RISC processorwhich is widely used by many universities in academic courses related to computer organization and architecture. Control unit design:. Control signals. ALU Control. ALU op. ALU Operation. R-type: ADD. R-type: sub.Not sure exactly what you're asking for - but here's a modified example of a simulation only manipulation of memory.

The left-hand argument can be a variable. The right hand argument the width must be constant. I want to simulate cache memory, so if the address not available in cache memory so bring 1 line 4 bytes from main memory.

You don't want to slice your memory index. That's for slicing your single bit word into 4 bytes.

I thought you were doing something else, and I've only confused things by bringing this up. It's a useful notation for indexing in to wide vectors - but for now, I think you need to focus on the basics. I'd suggest going back to your original code, and stepping through each line and understand what the tools is doing, and what you're trying to accomplish.

You've got examples now for how to address the elements within a memory both reads, and writes. Take a step back - review it, and maybe give things another attempt. Pay attention to the widths of all your signals.

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Create temporary registers of appropriate length if you need. Sign In Help. Turn on suggestions. Auto-suggest helps you quickly narrow down your search results by suggesting possible matches as you type.

Showing results for. Search instead for. Did you mean:. Anonymous Not applicable. All forum topics Previous Topic Next Topic. If it's just for simulation, there are a lot of ways to write memory. Mark How can change the code into manual formatYes, you are right. Just an example, modify it to whatever you want. That's only for debugging in simulation. You can commented it out in the top level code like John E if you don't want to see it in simulation.

Basic digital logic components in Verilog HDL. In this Verilog projectbasic blocks in digital logic design such as D-Flip-Flop, adders, ALU, registers, memory, multiplexers, decoders, counters, etc. What is an FPGA? Verilog code for FIFO memory 3. Verilog code for bit single-cycle MIPS processor 4.

Verilog code for basic logic components in digital circuits 6. Verilog code for bit Unsigned Divider 7. Verilog code for Fixed-Point Matrix Multiplication 8.

Verilog code for Carry-Look-Ahead Multiplier Verilog code for a Microcontroller Verilog code for 4x4 Multiplier Verilog code for Car Parking System Verilog code for Traffic Light Controller Verilog code for comparator design Verilog code for D Flip Flop Verilog code for Full Adder Verilog code for counter with testbench Verilog code for button debouncing on FPGA N-bit Adder Design in Verilog.

How to generate a clock enable signal in Verilog Verilog code for PWM Generator Verilog coding vs Software Programming.By using our site, you acknowledge that you have read and understand our Cookie PolicyPrivacy Policyand our Terms of Service.

Electrical Engineering Stack Exchange is a question and answer site for electronics and electrical engineering professionals, students, and enthusiasts. It only takes a minute to sign up. This is an almost complete body of Instruction Memory module. The thing I cannot understand is why we refer to the instruction in memory using address[ ]. I mean, why []? Because MIPS instructions are all 32 bits in length, bits 0 and 1 don't hold any meaning.

Therefore instead of looking at [] of the address it looks at []which is the translation for instructions. A stack the decimal numbers to the left are intended to be used for this brief explanation. The binary numbers to the right are the addresses of the instructions in the instruction memory the values aren't real. Just an example. In MIPS, an instruction is 4 byte long. That is why, as you can see from example above, that going from Instruct 1 l.

As Instruct 2 is reached, it is obvious that the first two bits in bold remain unchanged. Here, the first two bits have not changed. So the conclusion is: the first two bits doesn't tell us anything. They do not change as we go from instruction to instruction.

Verilog code for 16-bit single cycle MIPS processor

It's a good reason to neglect them. The ones that are useful are bits starting from position 2. Sign up to join this community. The best answers are voted up and rise to the top. Home Questions Tags Users Unanswered. Asked 3 years, 11 months ago.

instruction memory verilog code

Active 2 years, 11 months ago. Viewed 4k times. I've found an answer, but I cannot understand it. It says: What bits select the first words? Can you, please, explain me this detail in some other, more understandable way? Thank you.Thanks in advance. These files were given above.

Just create the file with the same names and copy the contents into these files. Thank you for the above code. I tested itworks perfectly. I got an overview now. Thanks again. For the instruction memory, you need to convert instructions to machine code. Then, put the data into instruction memory. There are 2 given example files for data and instruction memory. You can refer to it. Check register and memory content for verification or you take some of them as outputs to see on the simulation waveform.

Data Processing Instructions 1. Logical Shift Right:. Bitwise AND:. Bitwise OR:. Control Flow Instructions 1. Control signals. ALU Control. Opcode hex. ALU Operation. D-type: ADD. D-type: SUB. D-type: LSL. D-type: LSR. D-type: AND. D-type: OR. D-type: SLT.

Opcode instr[ 15 : 12 ]. Adding more instructions to verify your design is a good idea. We only use 8 data. Do not change this number.


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