lect12 FSM and memories

lect12 FSM and memories - CSE140: Components and Design...

Info iconThis preview shows pages 1–7. Sign up to view the full content.

View Full Document Right Arrow Icon
1 1 Sources: TSR, Katz, Boriello, Vahid CSE140: Components and Design Techniques for Digital Systems Tajana Simunic Rosing 2 Sources: TSR, Katz, Boriello, Vahid Announcements & Outline HW#7 due next Tuesday at 2pm FSM implementations: – Two level logic – Datapath/Control – Shift register – PAL with FFs Memory –ROM –R AM –F I FO – Queue Programmable Logic Devices (PLDs) Covered Chaps 9,10
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
2 3 Sources: TSR, Katz, Boriello, Vahid CSE140: Components and Design Techniques for Digital Systems FSM Implementations Tajana Simunic Rosing 4 Sources: TSR, Katz, Boriello, Vahid "puppet" "puppeteer who pulls the strings" control data-path status info and inputs control signal outputs state Data-path and control • Digital hardware systems = data-path + control – datapath: registers, counters, combinational functional units (e.g., ALU), communication (e.g., busses) – control: FSM generating sequences of control signals that instructs datapath what to do next
Background image of page 2
3 5 Sources: TSR, Katz, Boriello, Vahid Digital combinational lock • Door combination lock: – Press reset, then punch in 3 4 bit digits followed by enter, if the values match the code, the door opens; if there is an error the lock must be reset; once the door opens the lock must be reset – inputs: sequence of input values, reset – outputs: door open/close – memory: must remember combination or always have it available reset value open/closed new clock 6 Sources: TSR, Katz, Boriello, Vahid Digital combination lock state diagram • States: 5 states – represent point in execution of machine – each state has outputs • Inputs: reset, new, results of comparisons • Output: open/closed closed closed closed C1==value & new C2==value & new C3==value & new C1!=value & new C2!=value & new C3!=value & new closed reset not new not new not new S1 S2 S3 OPEN ERR open
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
4 7 Sources: TSR, Katz, Boriello, Vahid reset open/closed new C1 C2 C3 comparator value equal multiplexer controller mux control clock 4 44 4 4 Data-path and control structure • Data-path – storage registers for combination values – multiplexer – comparator • Control – finite-state machine controller – control for data-path (which value to compare) 8 Sources: TSR, Katz, Boriello, Vahid State table for a combination lock • Finite-state machine – refine state diagram to take internal structure into account – state table ready for encoding reset new equal state state mux open/closed 1–––S 1 C 1 c l o s e d 0 0 S 1S 1C 1c l o s e d 010S 1 E R R –c l o s e d 0 1 1 S 2C 2c l o s e d ... 011S 3 O P E N –o p e n ... next
Background image of page 4
5 9 Sources: TSR, Katz, Boriello, Vahid reset new equal state state mux open/closed 1 0001 001 0 0 0 0001 0001 001 0 0 1 0 0001 0000 0 0 1 1 0001 0010 010 0 ... 0 1 1 0100 1000 1 ... next reset open/closed new equal controller mux control clock Encodings for combination lock Encode state table 10 Sources: TSR, Katz, Boriello, Vahid C1 C2 C3 comparator equal multiplexer mux control 4 44 4 4 value Data-path implementation for combination lock • Multiplexer – easy to implement as combinational logic with few inputs
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
6
Background image of page 6
Image of page 7
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 25

lect12 FSM and memories - CSE140: Components and Design...

This preview shows document pages 1 - 7. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online