数字电子技术(floyd 第十版)课件chapter 2.ppt

6. An advantage of a ring counter over a Johnson counter is that the ring counter a. has more possible states for a given number of flip-flops b. is cleared after each cycle c. allows only one bit to change at a time d. is self-decoding 7. A possible sequence for a 4-bit ring counter is a. … 1111, 1110, 1101 … b. … 0000, 0001, 0010 … c. … 0001, 0011, 0111 … d. … 1000, 0100, 0010 … 8. The circuit shown is a a. serial-in/parallel-out shift register b. serial-in/serial-out shift register c. ring counter d. Johnson counter 9. Assume serial data is applied to the 8-bit shift register shown. The clock frequency is 20 MHz. The first data bit will show up at the output in a. 50 ns b. 200 ns c. 400 ns d. 800 ns ? 2008 Pearson Education 10. For transmission, data from a UART is sent in a. asynchronous serial form b. synchronous parallel form c. can be either of the above d. none of the above ? 2008 Pearson Education Answers: 1. a 2. c 3. c 4. a 5. b 6. d 7. d 8. d 9. c 10. a ? 2009 Pearson Education, Upper Saddle River, NJ 07458. All Rights Reserved Floyd, Digital Fundamentals, 10th ed ? 2009 Pearson Education, Upper Saddle River, NJ 07458. All Rights Reserved Floyd, Digital Fundamentals, 10th ed Digital Fundamentals Tenth Edition Floyd Chapter 9 ? 2008 Pearson Education A shift register is an arrangement of flip-flops with important applications in storage and movement of data. Some basic data movements are illustrated here. Summary Basic Shift Register Operations Data in Data in Data in Data in Data in Data out Data out Data out Data out Data out Serial in/shift right/serial out Serial in/shift left/serial out Parallel in/serial out Parallel in/parallel out Serial in/parallel out Rotate right Rotate left Summary Serial-in/Serial out Shift Register Shift registers are available in IC form or can be constructed from discrete flip-flops as is shown here with a five-bit serial-in serial-out register. Each cloc