2. Digital Electronics Electronics Technology Landon Johnson Shift Registers

4. Shift Register Competencies 39. Without references, the student will define the term “Serial Data Transmission” with 100% accuracy. 40. Without references, the student will define the term “Parallel Data Transmission” with 100% accuracy. 41. Without references, the student will define the acronym “SISO” with 100% accuracy. 42. Without references, the student will define the acronym “SIPO” with 100% accuracy.

5. Shift Register Competencies 43. Without references, the student will define the acronym “PISO” with 100% accuracy. 45. Given a specified register, the student will draw the register with 100% accuracy 44. Without references, the student will define the acronym “PIPO” with 100% accuracy. 46. Given a specified SISO or SIPO register, the student will state the number of pulses to completely load the register with 100% accuracy.

6. PARALLEL SHIFT REGISTER Lab 18.

7. SERIAL SHIFT REGISTER Lab 18.

8. SHIFT REGISTER VOCABULARY REGISTER- group of flip flops capable of storing data. SERIAL DATA TRANSMISSION- transfer of data from one place to another one bit at a time. PARALLEL DATA TRANSMISSION- simultaneous transfer of all bits of a data word from one place to another. SISO- SERIAL IN/SERIAL OUT- type of register that can be loaded with data serially and has only one serial output. SIPO- SERIAL IN/PARALLEL OUT- type of register that can be loaded with data serially and has parallel outputs available. PISO- PARALLEL IN/SERIAL OUT- type of register that can be loaded with parallel data and has only one serial output. PIPO- PARALLEL IN/PARALLEL OUT- type of register that can be loaded with parallel data and has parallel outputs available.

9. INTEGRATED CIRCUIT REGISTERS Lab 27. 74194A BIDIRECTIONAL UNIVERSAL SHIFT REGISTER

14. OVERVIEW OF SHIFT REGISTERS Common tasks of shift registers: – Serial/parallel data conversion – UART (an example) – Time delay – Ring counter – Twisted-ring counter or Johnson counter – Memory device A shift register is a sequential logic device made up of flip-flops that allows parallel or serial loading and serial or parallel outputs as well as shifting bit by bit.

15. CHARACTERISTICS OF SHIFT REGISTERS Number of bits (4-bit, 8-bit, etc.) Loading – Serial – Parallel (asynchronous or synchronous) Common modes of operation. – Parallel load – Shift right-serial load – Shift left-serial load – Hold – Clear Recirculating or non-recirculating

16. SERIAL/PARALLEL DATA CONVERSION 1 0 1 0 1 1 1 1 Serial in Serial out Shift registers can be used to convert from serial- to-parallel or the reverse from parallel-to-serial. 1 0 1 0 1 1 1 1 Serial in Parallel out 1 0 1 0 1 1 1 1 Serial out Parallel in 1 0 1 0 1 1 1 1 Parallel in Parallel out

17. SERIAL LOAD SHIFT REGISTER Note the use of D FFs. Clock (CLK) inputs wired in parallel. Clear (CLR) inputs can be activated with LOW or disabled with HIGH. Preset (PS) inputs deactivated. Parallel outputs here. Order= A B C D Inputs here: (1) Data (2) Clock (3) Clear Clear input: Active = 0 Deactivated = 1 Clock input: Positive-edge triggering Clock Pulse 1 Clear = 0 Data = 1 0 0 1 0 0 0 Clock Pulse 2 Clear = 1 Data = 1 1 1 0 00 1 1 0 Clock Pulse 3 Clear = 1 Data = 1 Clock Pulse 4 Clear = 1 Data = 0 0 0 1 1 Clock Pulse 5 Clear = 1 Data = 0 0 0 0 1 Clock Pulse 6 Clear = 1 Data = 0 Clock Pulse 7 Clear = 1 Data = 1 1 0 0 00 1 0 0 Clock Pulse 8 Clear = 1 Data = 0 4-bit serial-in parallel out shift right shift register

18. Clock Pulse 1 Clear = 0 Data = 1 Clock Pulse 2 Clear = 1 Data = 1 Clock Pulse 3 Clear = 1 Data = 0 Clock Pulse 4 Clear = 1 Data = 0 Clock Pulse 5 Clear = 1 Data = 1 QUESTION #1 This is a ___ type shift register. A. Serial-in, parallel out B. Parallel-in, serial-out A: Serial-in, parallel-out QUESTION #2 What is the 4-bit output (bit A on left, D on right) after pulse 1? A: 0000 QUESTION #3 What is the 4-bit output (bit A on left, D on right) after pulse 2? A: 1000 QUESTION #4 What is the 4-bit output (bit A on left, D on right) after pulse 3? A: 0100 QUESTION #5 What is the 4-bit output (bit A on left, D on right) after pulse 4? A: 0010 QUESTION #6 What is the 4-bit output (bit A on left, D on right) after pulse 5? A: 1001 QUESTION #7 What is the 4-bit output (bit A on left, D on right) after pulse 6? A: 1100 Clock Pulse 6 Clear = 1 Data = 1 TEST

19. PARALLEL LOAD SHIFT REGISTER Note the use of J-K FFs. Clock (CLK) inputs wired in parallel. Clear (CLR) input activated with LOW. Parallel load inputs (A,B,C,D) are active LOW. Note the recirculating lines. Outputs here. Order= A B C D Parallel data inputs (Active LOW) Clock input- H-to-L Clear input- Active LOW Recirculating lines: Pass data from FFD to FFA on each clock pulse.

20. RECIRCULATING SHIFT REGISTER 0 0 Clock pulse 1 Clear input= 0 Parallel data inputs= only D activated 0 0 1 1 Clock pulse 2 Clear input= 1 Parallel data inputs= C & D activated Clock pulse 3 Clear input= 1 Parallel data inputs= all inactive 1 0 0 1 Clock pulse 4 Clear input= 1 Parallel data inputs= all inactive 1 1 0 0 Clock pulse 5 Clear input= 1 Parallel data inputs= all inactive 0 1 1 0 Clock pulse 6 Clear input= 1 Parallel data inputs= all inactive 0 0 1 1 Clock pulse 7 Clear input= 0 Parallel data inputs= all inactive 0 0 Clock pulse 8 Clear input= 1 Parallel data inputs= only B active 0 1 0 0

21. UNIVERSAL SHIFT REGISTER IC 74194 Universal 4-bit Shift Register IC. Modes of operation: Hold, Parallel load, Shift right & Shift left. An active LOW Clear (CLR) input overrides all others. Outputs here Mode Controls: Hold Parallel load Shift right Shift left Clock input L-to-H triggering Parallel data inputs Order: A, B, C, D during Parallel loading Clear input active LOW Serial data Right input used during Serial Load Right mode of operation Serial data Left input used during Serial Load Left mode of operation

22. USING THE 74194 SHIFT REGISTER IC CLR = 1 Serial R = X Parallel Load= 0 1 1 0 Serial L = X Clock pulse 1 (L-to-H) S0= 1 S1= 1 0 1 1 0 X = Irrelevant CLR = 1 Serial R = 0 Parallel Load= 0 1 1 0 Serial L = X Clock pulse 2 (L-to-H) S0= 1 S1= 0 0 0 1 1 CLR = 1 Serial R = 0 Parallel Load= 0 1 0 0 Serial L = X Clock pulse 3 (L-to-H) S0= 1 S1= 0 0 0 0 1 CLR = 1 Serial R = 0 Parallel Load= 0 1 0 0 Serial L = X Clock pulse 4 (L-to-H) S0= 0 S1= 0 0 0 0 1 CLR = 0 Serial R = 0 Parallel Load= 0 1 0 0 Serial L = X Clock pulse 5 (L-to-H) S0= 1 S1= 1 0 0 CLR = 1 Serial R = X Parallel Load= 0 1 0 0 Serial L = X Clock pulse 6 (L-to-H) S0= 1 S1= 1 0 1 0 0 CLR = 1 Serial R = X Parallel Load= 0 1 0 0 Serial L = 1 Clock pulse 7 (L-to-H) S0= 0 S1= 1 1 0 0 1 CLR = 1 Serial R = X Parallel Load= 0 1 0 0 Serial L = 0 Clock pulse 8 (L-to-H) S0= 0 S1= 1 0 0 1 0

23. CLR = 0 Serial R = X Parallel Load= 0 1 0 0 Serial L = X Clock pulse 1 (L-to-H) S0= 1 S1= 1 ? ? CLR = 1 Serial R = 0 Parallel Load= 0 1 0 0 Serial L = X Clock pulse 2 (L-to-H) S0= 1 S1= 1 CLR = 1 Serial R = 0 Parallel Load= 0 1 0 0 Serial L = X Clock pulse 3 (L-to-H) S0= 1 S1= 0 CLR = 1 Serial R = 0 Parallel Load= 0 1 0 0 Serial L = X Clock pulse 4 (L-to-H) S0= 0 S1= 0 CLR = 1 Serial R = X Parallel Load= 0 1 0 0 Serial L = 1 Clock pulse 5 (L-to-H) S0= 0 S1= 1 QUESTION #1 The 74194 IC could be described as a 4-bit (shift right, universal) shift register. A: Universal QUESTION #2 What is the mode of operation during and the output of the shift register after pulse 1? A: Clear, 0 0 0 0 QUESTION #3 What is the mode of operation during and the output of the shift register after pulse 2? A: Parallel load, 0 1 0 0 QUESTION #4- What is the mode of operation during and the output of the shift register after pulse 3? A: Shift right, 0 0 1 0 QUESTION #5 What is the mode of operation during and the output of the shift register after pulse 4? A: Hold, 0 0 1 0 QUESTION #6 What is the mode of operation during and the output of the shift register after pulse 5? A: Shift left, 0 1 0 1 CLR = 1 Serial R = X Parallel Load= 0 1 0 0 Serial L = 1 Clock pulse 6 (L-to-H) S0= 0 S1= 1 QUESTION #7 What is the mode of operation during and the output of the shift register after pulse 6? A: Shift left, 1 0 1 1 TEST

24. SIMPLE TROUBLESHOOTING HINTS Feel top of IC to determine if it is hot Look for broken connections, signs of excessive heat Smell for overheating Check power source Trace path of logic through circuit Know the normal operation of the circuit