Download presentation
Presentation is loading. Please wait.
1
Single Cycle CPU
2
Operations Implemented
R-type add sub and or Load/Store ldur stur Conditional branch cbz Unconditional branch b
3
Register File Read Select D E C O R Data Out Write Select Data Out
M U X D E C O R Data Out Write Select M U X Data Out Write Enable Clock Data In Register File
4
R-Type Instruction Path
Rn Write ALU Rm Select Registers Rd R-Type Instruction Path
5
Load/Store Instruction Path
Rn ALU Registers Select Rt address Data Memory 1 M U X data out Sign Ext data in DT Addr Load/Store Instruction Path
6
Conditional Branch Instruction Path
PC + 4 ADD Shift Left 2 ALU Registers zero (to select condition) Select Rt Sign Ext Cond Br Addr Conditional Branch Instruction Path
7
Immediate Instruction Path (not implemented)
Rn Write ALU Registers Select Rd Zero Ext Immediate Immediate Instruction Path (not implemented)
8
Instruction Path with Instruction from Memory
PC + 4 ADD branch addr Shift Left 2 5-9 Write Zero ALU PC Instruction Memory 16-20 M U X Registers 0-4 address 1 M U X Data Memory 1 data out M U X 0-31 Sign Ext data in Instruction Path with Instruction from Memory (R-type, Load/Store, Conditional branch, no immediate)
9
Incrementing the Program Counter and computing branch address
4 ADD PC + 4 ADD branch addr Shift Left 2 5-9 Zero ALU PC Instruction Memory 16-20 M U X Registers 0-4 address 1 M U X Data Memory 1 data out M U X 0-31 Sign Ext data in
10
4 Zero ADD ADD ALU PC Instruction Memory Registers Data Memory M U X
1 M U X 4 ADD ADD Shift Left 2 5-9 ALU PC Instruction Memory 16-20 Zero M U X Registers 0-4 address 1 M U X Data Memory 1 M U X data out data in 0-31 Sign Ext
11
4 Zero ADD ADD ALU PC Instruction Memory Registers Data Memory M U X
1 M U X ADD 4 ADD Shift Left 2 C O N T R L A B C D E F G H 21-31 5-9 write ALU PC Instruction Memory 16-20 Zero M U X Registers write read 0-4 1 address M U X Data Memory 1 M U X data out Sign Ext data in 0-31 ALU CTRL 21-31
12
Control Lines, Top to Bottom
A Conditional Branch (CBZ) B MemToReg C MemRead D MemWrite E ALUSrc F ALUOp G RegWrite H Reg2Loc
13
Start to 2 ns 4 Zero ADD ADD ALU PC Instruction Memory Registers Data
1 M U X ADD 4 ADD Shift Left 2 C O N T R L A B C D E F G H 21-31 5-9 write ALU PC Instruction Memory 16-20 Zero M U X Registers write read 0-4 1 address M U X Data Memory 1 M U X data out Sign Ext data in 0-31 Start to 2 ns ALU CTRL 21-31
14
R-Type Register Rd 2 - 3 ns 4 Zero ADD ADD ALU PC Instruction Memory
1 M U X ADD 4 ADD Shift Left 2 C O N T R L A B C D E F G H 21-31 5-9 write ALU PC Instruction Memory 16-20 Zero M U X Registers write read 0-4 1 address M U X Data Memory 1 M U X data out R-Type Register Rd 2 - 3 ns Sign Ext data in 0-31 ALU CTRL 21-31
15
R-Type ALU 3 - 5 ns 4 Zero ADD ADD PC Instruction Memory Registers ALU
1 M U X ADD 4 ADD Shift Left 2 C O N T R L A B C D E F G H 21-31 5-9 write PC Instruction Memory 16-20 Zero M U X Registers ALU write read 0-4 1 address M U X Data Memory 1 M U X data out R-Type ALU 3 - 5 ns Sign Ext data in 0-31 ALU CTRL 21-31
16
R-Type Reg Write 5 - 6 ns 4 Zero ADD ADD PC Instruction Memory
1 M U X ADD 4 ADD Shift Left 2 C O N T R L A B C D E F G H 21-31 5-9 write PC Instruction Memory 16-20 Zero M U X Registers ALU write read 0-4 1 address M U X Data Memory 1 M U X data out R-Type Reg Write 5 - 6 ns Sign Ext data in 0-31 ALU CTRL 21-31
17
Load D-Word 0 - 2 ns 4 Zero ADD ADD ALU PC Instruction Memory
1 M U X ADD 4 ADD Shift Left 2 C O N T R L A B C D E F G H 21-31 5-9 write ALU PC Instruction Memory 16-20 Zero M U X Registers write read 0-4 1 address M U X Data Memory 1 M U X data out Load D-Word 0 - 2 ns Sign Ext data in 0-31 ALU CTRL 21-31
18
Load D-Word Reg Read 2 - 3 ns 4 Zero ADD ADD ALU PC Instruction Memory
1 M U X ADD 4 ADD Shift Left 2 C O N T R L A B C D E F G H 21-31 5-9 write ALU PC Instruction Memory 16-20 Zero M U X Registers write read 0-4 1 address M U X Data Memory 1 M U X data out Load D-Word Reg Read 2 - 3 ns Sign Ext data in 0-31 21-31 ALU CTRL
19
Load Word Address Comp 3 - 5 ns 4 Zero ADD ADD PC Instruction Memory
1 M U X ADD 4 ADD Shift Left 2 C O N T R L A B C D E F G H 21-31 5-9 write PC Instruction Memory 16-20 Zero M U X Registers ALU write read 0-4 1 address M U X Data Memory 1 M U X data out Load Word Address Comp 3 - 5 ns Sign Ext data in 0-31 21-31 ALU CTRL
20
Load D-Word Memory Access 5 - 7 ns 4 Zero ADD ADD PC Instruction
1 M U X ADD 4 ADD Shift Left 2 C O N T R L A B C D E F G H 21-31 5-9 write PC Instruction Memory 16-20 Zero M U X Registers ALU write read 0-4 1 address M U X Data Memory 1 M U X data out Load D-Word Memory Access 5 - 7 ns Sign Ext data in 0-31 21-31 ALU CTRL
21
Load D-Word Write Back 7 - 8 ns 4 Zero ADD ADD PC Instruction Memory
1 M U X ADD 4 ADD Shift Left 2 C O N T R L A B C D E F G H 21-31 5-9 write PC Instruction Memory 16-20 Zero M U X Registers ALU write read 0-4 1 address M U X Data Memory 1 M U X data out Load D-Word Write Back 7 - 8 ns Sign Ext data in 0-31 21-31 ALU CTRL
22
CBZ 0 - 2 ns 4 Zero ADD ADD ALU PC Instruction Memory Registers Data
1 M U X ADD 4 ADD Shift Left 2 C O N T R L A B C D E F G H 21-31 5-9 write ALU PC Instruction Memory 16-20 Zero M U X Registers write read 0-4 1 address M U X Data Memory 1 M U X data out CBZ 0 - 2 ns Sign Ext data in 0-31 ALU CTRL 21-31
23
CBZ Register Rd 2 - 3 ns 4 Zero ADD ADD ALU PC Instruction Memory
1 M U X ADD 4 ADD Shift Left 2 C O N T R L A B C D E F G H 21-31 5-9 write ALU PC Instruction Memory 16-20 Zero M U X Registers write read 0-4 1 address M U X Data Memory 1 M U X data out CBZ Register Rd 2 - 3 ns Sign Ext data in 0-31 21-31 ALU CTRL
24
CBZ taken ALU test 3 - 5 ns 4 Zero ADD ADD PC Instruction Memory
1 M U X 4 ADD ADD Shift Left 2 C O N T R L A B C D E F G H 21-31 5-9 write PC Instruction Memory 16-20 Zero M U X Registers ALU write read 0-4 1 address M U X Data Memory 1 M U X data out CBZ taken ALU test 3 - 5 ns Sign Ext data in 0-31 21-31 ALU CTRL
25
Unconditional branch added (AA)
1 M U X ADD 4 ADD Unconditional branch added (AA) Shift Left 2 C O N T R L AA A B C D E F G H 21-31 5-9 write ALU PC Instruction Memory 16-20 Zero M U X Registers write read 0-4 1 address M U X Data Memory 1 M U X data out Sign Ext data in 0-31 Additional logic In Sign Ext ALU CTRL 21-31
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.