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- 1. SR Latch using NAND Gate
- 2. Truth table of JK-ff ,D-ff, T-ff
- 3. D & T- FF FROM JK FF
- 4. COUNTERS # used to count binary events/sequence. #A counter circuit is usually constructed of a number of flip flops connected in cascade. #Counters are generally designed by using JK FF/ T type/DType flip flops. #If n is a number of FF, then no. of events that a counter can count will be 2n a counter with three flip-flops like the circuit above will count from 0 to 7 ie, 2n-1. It has eight (events)different output states representing the decimal numbers 0 to 7 and is called a Modulo- 8 or MOD-8 counter. An example of this is given as. 3-bit Binary Counter = 23 = 8 (modulo-8 or MOD-8) 4-bit Binary Counter = 24 = 16 (modulo-16 or MOD-16) 8-bit Binary Counter = 28 = 256 (modulo-256 or MOD-256) and so on.. #It is also called frequency divider
- 5. TYPES 1.Asynchronous (ripple) counter /Serial Counter a) up counter b)Down conter c) UP/Down Counter Out put of previous stage is clock of next stage 2.Synchronous counter/parallel Counter a) up counter b) down counter c) UP/Down Counter Same clock is used for all flip flop. 3. modulus counter (eg.Decade counter i.e. mod10 counter) 4.Ring counter 5.Johnson counter
- 6. Two Bit UP Counter (ASYNCHRONOUS)
- 8. 3 bit up counter
- 13. Two bit up/Down counter (Asynchronous) UP Counting If the UP input and down inputs are 1 and 0 respectively DOWN Counting If the DOWN input and up inputs are 1 and 0 respectively
- 14. Two Bit UP Counter (SYNCHRONOUS)
- 15. Two Bit UP Counter (SYNCHRONOUS)
- 16. To increase counting level Next stage is connected through Nand gate as shown..
- 17. 3 bit synchronous up counter
- 21. Two Bit down Counter (SYNCHRONOUS)
- 23. 2 BIT UP DOWN COUNTER (synchrous) When UP/DOWN = 0, the counter counts down... When UP/DOWN = 1, the counter counts up...
- 24. Modulus counter Decade counter The NAND gate outputs are connected to the CLR input of each of the FFs." A decade counter is one that counts in decimal digits, rather than binary. It counts from 0 to 9 and then resets to zero. Thecounter output can be set to zero by pulsing the reset line low.
- 26. Ring counter A ring counter is a type of counter composed of flip-flops connected into a shift register, with the output of the last flip-flop fed to the input of the first, making a "circular" or "ring" structure.
- 27. Ring counter A ring counter of n-bits has only n valid states instead of 2n
- 29. Johnson Counter. A Johnson counter is a modified ring counter, where the inverted output from the last flip flop is connected to the input to the first. The register cycles through a sequence of bit-patterns. The MOD of the Johnson counter is 2n if n flip-flops are used.
- 30. n bit Johnson counter to be MOD 2n in-nature
- 32. Shift Registers A shift register is a type of digital circuit using a cascade of flip-flops where the output of one flip-flop is connected to the input of the next. They share a single clock signal, which causes the data stored in the system to shift from one location to the next. We know that one flip-flop can store one-bit of information. In order to store multiple bits of information, we require multiple flip- flops. The group of flip-flops, which are used to store the binary data is known as register. If the register is capable of shifting bits either towards right hand side or towards left hand side is known as shift register. An N bit shift register contains N flip-flops. Following are the four types of shift registers based on applying inputs and accessing of outputs. Types SISO SIPO PISO PIPO
- 37. Thankyou There is no substitute of hard work