Download - Decoder
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Decoder
Mano Section 4.9
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Outline
• Decoder• Applications• Verilog
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Example of a Decoder
Convert binary information from n input lines to 2n unique outputlines.
This particular circuit take a binary number and convert it to an octal number.
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Hardware Implementation
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AND and NOR Decoders
Take an n-bit address.Produce 2n outputs,One of which is activated.
(NOR Decoder)
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Organization of Memory Systems
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Basic SRAM and VTC
A wordline is used to select the cellBitlines are used to perform read and write operations on the cell
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Cross Coupled Configuration
The cell can only flip its internal state when one of its internal cross VS.During a read op, we must not disturb its current state.During a write op, we must force the internal voltage to swing past VS to change a state.
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A 2-to-4 decoder with Enable
(typo, should be a 0)
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Demultiplexer
A Demux is a circuit that receives information from a singleline and directs it to one of 2n possible output lines.
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Use a 2-to-4 decoder as a Demux
(typo, should be a 0)
Treat A and B as the selector bits. i.e. A and B select which bit should receive infomraiton.E is treated as the data line.
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Implement a Full Adder with a Decoder
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Build a Bigger Decoders
Use w to enable either top or bottom decoder.
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3-to-8 decoder in verilog
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3-to-8 decode
Input bits
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Use a Test Bench to Generate output
Initial statements execute oncestarting from time 0.
$monitor: display variable whenever a value changes.$time display the simulation time
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Run functional Simulation
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Results