in detail about the SHIFT-REGISTER-ppt.ppt
- 1. Last Mod: March 2008 Paul R. Godin Perancangan Rangkaian sekuensial Registers 1.1 Pertemuan 2 SHIFT REGISTER
- 2. Shift Register Applications Shift Registers are an important Flip-Flop configuration with a wide range of applications, including: Computer and Data Communications Serial and Parallel Communications Multi-bit number storage Sequencing Basic arithmetic such as scaling (a serial shift to the left or right will change the value of a binary number a power of 2) Logical operations Registers 1.2
- 3. Parallel versus Serial Serial communications: provides a binary number as a sequence of binary digits, one after another, through one data line. Parallel communications: provides a binary number as binary digits through multiple data lines at the same time. Registers 1.3
- 4. Shift Registers Shift Registers are devices that store and move data bits in serial (to the left or the right), ..or in parallel, ..or a combination of serial and parallel. Registers 1.4
- 5. Configuration In Shift Registers, the binary digit transfers (shifts) from the output of one flip-flop to the input of the next individual Flip-Flop at every clock edge. Once the binary digits are shifted in, the individual Flip-Flops will each retain a bit, and the whole configuration will retain a binary number. Registers 1.5
- 6. Construction Shift registers are constructed from flip-flops due to their characteristics: Edge-triggered devices Output state retention Each Flip-Flop in a shift register can retain one binary digit. For instance, if a 5-bit binary number needs to be stored and shifted, 5 flip-flops are required. Each binary digit transfer operation requires a clock edge. Asynchronous inputs are useful in resetting the whole configuration. Registers 1.6
- 7. Shift Register Construction Shift registers are comprised of D Flip-Flops that share a common clock input. D Q Q D Q Q D Q Q Registers 1.7
- 8. Combinations of Data Transfer Methods SISO: Serial In, Serial Out SIPO: Serial In, Parallel Out PISO: Parallel In, Serial Out PIPO: Parallel In, Parallel Out How many clock edges are required for each operation? 10110 10110 10110 10110 10110 10110 10110 10110 Registers 1.8
- 9. SISO Flip-Flop Shift Register a Serial In Serial Out shift register has a single input and a single output D Q Q D Q Q D Q Q Input Output Registers 1.9
- 10. SIPO Flip-Flop Shift Register a Serial In Parallel Out shift register has a single input and access to all outputs D Q Q D Q Q D Q Q Input Output Output Output Registers 1.10
- 11. PISO Flip-Flop Shift Register a Parallel In Serial Out shift register requires additional gates, and the parallel input must revert to logic low. Input D Q Q Input Output Input D Q Q D Q Q Registers 1.11
- 12. PIPO Flip-Flop Shift Register a Parallel In Parallel Out register has the simplest configuration. It represents a memory device. D Q Q Input Output D Q Q Output D Q Q Output Input Input Registers 1.12
- 13. Universal Shift Registers Universal Shift Registers can be configured to operate in a variety of modes. For instance, they can be configured to have either Serial or Parallel Input/Output. Internally use steering gates to determine: Serial input/output direction Parallel input (load) Hold Refer to the manufacturer specification sheets for more information. Registers 1.13
- 14. Registers 1.14 Universal Shift Registers Look up the 74LS194 and describe its function by looking at the schematic. Fill in the table. S0 S1 Mode 0 0 0 1 1 0 1 1 In-class exercise 14
- 15. Application: Parallel transferring the contents of a Register to another register. Describe where this circuit combination may be used. Registers 1.15
- 16. JK Shift Registers J-K Shift registers are seldom used, as two inputs (J,K) are required to load the first flip-flop (note all others receive only set or reset inputs). Input Output J Q K Q J Q K Q J Q K Q Input Registers 1.16
- 17. Ring Counter A ring counter takes the serial output of the last Flip-Flop of a shift register and provides it to the serial input of the first Flip-Flop. Ring Counters are also known as re-circulating shift registers. The display characteristics will be familiar… Registers 1.17
- 18. Ring Counter In Class: Build a ring counter using electronics simulation tools Registers 1.18
- 19. Self-Starting or Load on Power-up There are several ways of loading values into a ring counter on power-up: RC circuit Logic detection (similar to truncating a counter) Registers 1.19
- 20. Johnson Counter A Johnson Counter re-circulates the last flip- flop Q (inverted) output back to the input of the first Flip-Flop. It doesn’t require an initialization value, and will provide a predictable output state sequence. Registers 1.20
- 21. Re-Circulating Counters Johnson Counter 0000 1000 1100 1110 1111 0111 0011 0001 A 4-bit Johnson counter has a modulus of 8, meaning there are 8 unique output states. 8 unique states Registers 1.21
- 22. State Diagram A State Diagram is used to describe the sequence of output states of a circuit. The state diagram for the previous Johnson counter looks like this: 1000 1100 1110 1111 0111 0011 0001 0000 Registers 1.22
- 23. Registers 1.23 State Recognition One application of registers is to recognize a specific binary number. Sequences of bits are loaded in series into a register. External detection gates will identify if the value matches a predetermined value: What value will this circuit detect? Will this work with a Johnson counter? 23
- 24. Registers 1.24 Comparison of two values Values stored in shift registers can be compared by using the following circuit : What is the output be if both binary inputs are the same? 24
Editor's Notes
- #25: Tugas : Dgn multisim sim simulasikan Ring Counter dan Johnson Counter