Questions tagged [cpu]
The CPU, the Central Processing Unit, is known as the heart of the computer. It is responsible for carrying out the instructions of a computer program by performing the basic arithmetic, logical, control, and input/output (I/O) operations specified by the instructions.
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Which address bit width should I choose for my single cycle CPU (Logisim)
I am currently designing a MIPS single cycle CPU (32 bits) in Logisim
I have already implemented the PC, instruction memory, register file and ALU. Since it is a 32 bits system I understand that the ...
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Are iGPUs utilized in any way while using a discrete GPU? Could they? Should they?
Whenever I've seen die shots of CPUs that contain integrated GPUs, it seems that the GPU takes up a not-insignificant portion of the die.
(Source: AMD "Phoenix 2" die shot, purely an ...
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Problem with 5-staged pipeline CPU design
We are doing a project designing a 5 staged pipelined CPU on RISC-V ISA, when designing the hazard detection unit and forwarding unit, instead of using the common datapath design, we design like this:
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does data and instruction memory we see in the data path corresponds to the L1 Instruction and Data cache inside of the core?
In CPU data path there are blocks called data memory and instruction memory ? Are these blocks L1 Instruction and L1 data caches ?
For instance check figure 4.10 in this link.
We know that generally ...
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How to implement the Instruction Set in Logisim
I have an assignment that requires me to build an 7-bit CPU. I’m done with implementing some of the requirements that includes 4 8-bit registers (the requirements say I have to store the parity bit), ...
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What Specific Optimizations Can ARM Implementations Do That x86 Ones Cannot (And Vice-Versa And Risc-V)
I believe this question is slightly different from others (ex: Why exactly does the x86 (primarily x86-64) instruction set consume more power than reduced instruction sets like arm?)
This question is ...
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Why Does MIPS IF.Flush Signal come out of the control unit?
I was reading about MIPS pipelining, specifically, the part on dealing with branching through predictions by assuming a branch is not taken, then adding nops if the ...
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Why forward from MEM Stage in a sequence of add instructions that all contain the same register?
I was reading Computer Architecture and Organization 5th edition by Patterson and Hennessy. In Chapter 4, section 4.7 on Data Hazards, I read the following excerpt regarding forwarding from the MEM ...
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Were vacuum tube computers made of logic gates?
A lot of introductory resources on modern CPU present them as being built from NAND gates (see here and there for instance).
Actually, it is possible to build a modern CPU using almost exclusively ...
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How is the address line A20 enabled in modern hardware?
In the olden times, the memory address line 20 (A20) of the 80286 and others was automatically masked by the IBM AT motherboard. It could be enabled using the keyboard controller. Then the 80486 ...
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Wrong value in memory because of a branch misprediction
Lets say we have instructions like:
bne r1 $0 loop
sw r2 0(r1)
Let's say we go ahead with the taken path, i.e., execute the sw instruction after bne assuming the ...
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Configuring CPU with the reversed power polarity
My question comes from a pure curiosity. I initially wrote that it has no practical value, but in the process of writing I came to the idea that one (e.g. an intruder) can potentially use it to ...
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Is a feedback loop from program counter input to output problematic?
I'm designing a very simple CPU to be built on a custom PCB. I designed the CPU in LogicCircuit, and it seems to work. But I'm wondering it a specific part of the CPU will also work in real life.
I ...
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What is the communication protocol used by non-expansion card USB ports to communicate with CPU?
USB ports can come as expansion cards, like this:
Now obviously, since this is a PCIe USB card, the communication protocol used by this expansion card to communicate with CPU is PCIe.
But what about ...
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Is it possible to make the "arithmetic" part of the ALU to be mircoprogrammed?
We know that the Arithmetic and Logic Unit in CPU is a hardware, it is a combinational circuit. Binary addition, for example, is very fast because it doesn't have to be microprogrammed; there is ...
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