mohd. yamani idris/ noorzaily mohamed noor 1 sequential circuit: register introduction n-bit...

MOHD. YAMANI IDRIS/ NOORZAILY MOHAMED NOOR

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Sequential Circuit: Register

Introduction N-bit register contains n flip-flop and several

logic gates and able to store n-bit information Flip-flop stores information and logic gates

control when and how new information transferred into register

Several register functionality Fetch data from register Store/load new data into register (serial or parallel) Shift data into register (right or left)


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Simple register No external gate Example: 4-bit data. 4-bit new data is loaded

each clock cycle


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Register with parallel load Other than load register at each clock cycle, we

also need to control when it will be loaded Loading register: load new information into

register. Needed control input “load” Parallel loading: all bit is loaded simultaneously


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With parallel load


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Shift Register Other function of register, other than storage is

data movement Each flip-flop in shift register represent one bit

storage and data shift ability provide data movement space from one level to another level in register or into or out the register based on clock pulse


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Shift Register Basic movement in shift register (this diagram is

for 4-bit shift register)


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Serial In/Serial Out Shift Register Received data serially – one bit at a time and

produce serial output


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Serial In/Serial Out Shift Register Usage: transfer data serially from register to

register


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Serial In / Serial Out Shift Register Example: transfer data serially


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Serial In / Serial Out Shift Register Received data serially Output simultaneously


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Parallel In / Serial Out Shift Register Received parallel data (bit enter simultaneously) Serial Output (one by one)


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Parallel In / Serial Out Shift Register Received parallel data (bit enter simultaneously) Serial Output (one by one)


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Parallel In / Parallel Out Shift Register Received data simultaneously and exit

simultaneously


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Bidirectional Shift Register Data can be shifted either left or right using

RIGHT/LEFT control gate to determine direction


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Bidirectional Shift Register 4-bit Bidirectional Shift Register with parallel load


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Bidirectional Shift Register 4-bit Bidirectional Shift Register with parallel load


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Bidirectional Shift Register Usage

Serial Addition Shift Register Counter Ring Counter Johnson Counter


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Sequential Circuit: RAM

Introduction to Random Access Memory - RAM Memory unit which store binary information in group of bit

called “word” Data consist of n line (for n-bit word). Data input line

prepare information to be stored (write) into memory yet output data line brings information out (read) of memory

Address consist of k-line which determine which word (between 2k word) for read or write.

Read/Write control line determine data transition direction either for read or write.


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Random Access Memory (RAM) Memory unit block diagram


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Random Access Memory (RAM) Contains 1024x16bit memory


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Random Access Memory (RAM) Write Operation

Send address for related “word” to address line Send data bit (word) which will be stored into memory

to input data line Activate write control line (set Read/Write to 0)

Read Operation Send address for related “word” to address line Activate read control line (set Read/Write to 1)


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Random Access Memory (RAM) Write Operation

Send address for related “word” to address line Send data bit (word) which will be stored into memory

to input data line Activate write control line (set Read/Write to 0)

Read Operation Send address for related “word” to address line Activate read control line (set Read/Write to 1)


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Random Access Memory (RAM) Read/Write Operation

Two types of RAM: Static and Dynamic Static RAM use flip-flop as memory cell Dynamic RRAM use capacitor charge to represent data.

Simple circuit and always need to be charge again


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Random Access Memory (RAM) Read/Write Operation

Two types of RAM: Static and Dynamic Static RAM use flip-flop as memory cell Dynamic RRAM use capacitor charge to represent data.

Simple circuit and always need to be charge again


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Random Access Memory (RAM) The following logic and block diagram shows

one memory cell for static RAM


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Random Access Memory (RAM) Logical built for 4x4 RAM (with decoder and OR

gate)


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Random Access Memory (RAM) Array for RAM chips: memory chip is combined

to form larger size memory 1K x 8-bit RAM chip


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Random Access Memory (RAM) 4K x 8-bit RAM chip

mohd. yamani idris/ noorzaily mohamed noor 1 sequential circuit: register introduction n-bit...

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