Tag: Computer Architecture

intro - where are we now?

the cpu

Processor - datapath - control

cenario in RISC-V machine

The datapath and control

Overview

• problem: single monolithic bloc
• solution: break up the process of excuting an instruction into stages
  • smaller stages are easier to design –
  • easy to optimize &modularity

five stages

• Instruction Fetch
  • pc+=4
  • take full use of mem hierarchy
• Instruction Decode
• read the opcode to determine instruction type and field lengths
• second, (at the same time!) read in data from all necessary registers
  • for add, read two registers
  • for addi, read one register
• third, generate the immediates
• ALU
  • the real work of most instructions is done here: arithmetic (+, -, *, /), shifting, logic (&, |)
  • For instance, it's load and store
    • lw t0, 40(t1)
    • the address we are accessing in memory = the value in t1 PLUS the value 40
    • so we do this addition in this stage
• Mem access
  • Actually only the load and store instruction do anything during this stage.
  • it's fast but unavoidable
• Register write
  • write the result of some computation into a register.
  • for stores and brances idle
    

    misc

    

  

  memory alignment

  

data path elements state and sequencing

register

instruction level

add

time diagram for add

addi

lw

sw - critical path

combined I+S Immediate generation

branches

pipelining

summary

quiz

for D

for E

CS 150 is composed of the TsingHua's 计算机组成原理 and VSLI

source:http://www-inst.eecs.berkeley.edu/~cs150/sp13/agenda/

They studied verilog

FSM is really similar to our homework. actually, I found that their exams is given to us for homework.

P.S.: WHY they have spring break?

run a linux on FPGA. and implement a CPU. 俗称“造机”。

If I have time, I'll implement the CPU by my own.

GPU applying the RISC-V architecture will be much better and cooler.

The more I read and learn , the more I found the knowledge in the EECS category can be nicely cascaded. In most of the cases, we get the point from another place and we can be taught within minutes.

After talking with upperclassman 罗浩聪, I guadully find my career as an PhD in Arch or PL, or sth, in between. But for now, let me finish the 2 cooperate papers.

intro

synchronous digital systems

Hardware of a processor should be synchronous and digital

The hardware layer of abstraction

switches

arrow shows action if wire changes to 1 or is asserted.

and & or

Transistors

High voltage$V_{dd}$ Low voltage \(Gnd\)

PWD

we implement switches using CMOS

CMOS Transistor Network

vs

note PWD

material:

how MOSFET Operation

CMOS Networks

2 input network

combined logit symbols

example debugging waveform

types of circuits

CL

SL

example using time chart

Language Execution continuum

An interpreter is a program that executes other programs.

1. langurage translation gives us another option
2. In genreral, we interpret a high-level language to a lower-level language to increase preformance

interpretation

1. Python
2. asm

Assembler directives

pseudo-instruction replacement

what's tail's about

{...
 lots of code
 return foo(y);
}

• it's recursive call to foo() if this is within foo(), or call to a different function...
• for effictiency
  • Evaluate the arguments for foo() in a0-a7
  • return ra, all callee saved registers and sp
  • Then call foo() with j or tail
• when foo() returns, it can return directly to where it needs to return to
  • Rather than returning to wherever foo() was called and returning from there
  • Tail call optimization

branches

Linking progress

Four types of Address

PC- relative addredding (beq)

Absolute addresses in RISC-V

Loading process

Clarifications

Project 1 RISC-v emulator

1. Risc-v isa does not define assembly syntax
   behave exactly like Venus
2. All I-Type instructions (including sltiu)
   • do sign-extension
   • (in venus) input number is signed, even if hex

a good tool

Interpretation

1. any good reason to interpret machine language in software? debbuger Venus
   
2. translated/compiled code almost always more efficitent and therfore higher performance:
   • important for many applications, particularly operating systems.
3. 

Steps in compiling a C program

Psuedo-instruciton Replacement

Producing Machine Language

• simple case
  • arithmetic, logical, shifts and so on
  • All necessary info is within the instruction already
• branches can be optimized