controllers
DESCRIPTION
THIS PPT CONTAINS DETAILS OF A CONTROLLER SYSTEM USED IN DATA DESIGNING OF DIGITAL CIRCUITS. IT ALSO CONTAINS ITS IMPLEMENTATION..TRANSCRIPT
04/13/2023CONTROLLERS 1
CONTROLLERS
RAVITESH MISHRAASST. PROFESSOR
BCE,MANDIDEEP
04/13/2023CONTROLLERS 2
It is a special sequential machine.
It interpret system level control input
sequences.
Receives input from each component &
generate control signals for the system.
It becomes nervous centre for the system.
SYSTEM CONTROLLER
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1 Define purpose & role of system.
2 Define basic operation & limitations to handle.
3 Define time & frequency of system I/O.
4 Detail its sequential behaviour.
5 Develop MDS (Mnemonic Documented State) diagram.
6 Choose sysytem controller architecture & synchronizers.
7 Make state assignment.
CONTROLLER DESIGN PHASE
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IMPLEMENTATION OF CONTROLLER
1. RANDOM LOGIC2. Implemented with mealy or
moore machine similar to sequential circuits.
USING ROMNext state decoder & output decoder is replaced by ROM or PROM
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IMPLEMENTATION OF CONTROLLER (Cont.)
USING COUNTERS
Use counter in place of memory.
Any multimode counter can be used with specification
1) asynchronous clear 2) synchronous load 3) count enable
control
Qualities of counter
Count and branch conditionally and unconditionally.
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MICROPROGRAM CONTROLLERMicroprogrammed
Controller:Micro instruction is used & stored in contro memory when executed generazte controlSignals.Next Address Generator:Generate address of nextmicroinstruction.
Control Address Registration:
Specifies address ofmicroinstruction.
Control Memory:Stores the microinstruction.
04/13/2023CONTROLLERS 7
ADVANTAGES
1 Regular & computation independent
structure.
2 Change the Structure by reprogramming.
3 It replaces the bulky hardware.