ECE 353 Lab B (part 1 – Overview)

1. ECE 353 Lab B(part 1 – Overview) Prof. Sandip Kundu

2. Brief Intro of Instructor • @UMass for 9 years • Previously • Principal Engineer @ Intel • 1997-2005 • Member of Research Staff at IBM Research • 1988-1997 • Research Interests • Processor Design: 242 • VLSI Circuit Design: 558. 559 • VLSI Testing: 654 • Design for Manufacturability: 697 • Authored multiple books and research papers

3. Class Information • http://ece353.ecs.umass.edu • Labs B and D • Office hours during Lab B and D • Tu 10AM-11AM • Or send email for appointment • Grading • Lab B and Lab D equal weight (each 50% of 35% of final grade) • Will grade demo and code/report • Final exam (30% of grade) – 50% of questions from Lab B/D

4. Outline • Lab B Overview • Next Lecture Review of Design with Verilog for Lab B • Hands-on Lab B • We will provide information about common issues to watch out for • Demo by UGAs • We will go through a functional system so that you can see the end result in class

5. In this lab, you will… • Design and implement a serial MIDI receiver • Essentially a serial port for the MIDI device that will read a MIDI signal • Interpret its content • Display the note number in binary on seven LEDs. • MIDI signal from PC (soundcard) • Musical notes played using PC keyboard & MIDI OX (“the world's greatest all-purpose MIDI Utility” is free at www.midiox.com). The notes played on the computer’s keyboard will cause MIDI serial data to be sent serially out the MIDI OUT connector.

6. In this lab, you will… (contd.) • be Coding in Verilog • Hardware in an Altera Complex Programmable Logic Device (CPLD) MAX 7000S (part number EPM7064SLC44-10) • Using ALTERA Quartus II software tools for synthesis • Wire up and program on board • Debug - functional simulation (wave forms) • Debug of board - logic analyzer

7. Review MIDI • Musical Instrument Digital Interface • Developed in 1980s • Common hardware interface and protocol • Allows electronic musical devices to communicate with each other • MIDI messages are transmitted asynchronously • Like UART – Universal Asynchronous Receiver Transmitter • UART is more flexible with many more parameters no char ... bit 0 bit 1 bit n-1 stop start time

8. 0 1 2 3 4 5 6 7 LSB Idle MSB 1 0 STOP bit START bit Data word MIDI Specification • Groups of bytes, typically three • Each byte with START and STOP bit • Status byte – code for Note On, Off, other ctrl, ChID – MSB bit is on (1) • Data bytes – MSB bit is off (0) • 2nd B: Note On or Off message with note number • 128 different notes, 10 octaves • 3rd B: Note On or Off with velocity (how hard is instr. pressed)

9. @8.5 BT @2.5 BT @1.5 BT frame 1 frame 2 frame 3 idle idle 8 bits 8 bits 8 bits stop start stop start stop start Decoding of a MIDI Message • In your work you will be decoding MIDI • 31,250 bits/s fixed baud rate, bit time (BT) 32us • With START & STOP a MIDI msg is 10BT, 320us • You see this with wave form • Consecutive frames separated by undefined time

10. @8.5 BT @2.5 BT @1.5 BT frame 1 frame 2 frame 3 idle idle 8 bits 8 bits 8 bits stop start stop start stop start Decoding of MIDI (contd.) • Board has a 4MHz clock that you need to divide (or count) • Before a frame, signal line is high • The receive must wait for 0 and detect neg edge • Now start sampling 8 bits (payload) in the middle • See below at 1.5BT, …8.5BT • Stop at 9.5 BT, that is the STOP bit • Repeat for each byte

11. Decoding of MIDI (contd.) • Sampled value at 9.5BT is not logic 1? • A MIDI receiver sets a flag “Framing Error” • You can implement if you want (not required) • Sampling at least once per bit but commonly more times and vote • A voter has a number of inputs and generates an output based on e.g., majority or plurality of inputs • TMR (Triple Modulo Redundancy) voter would vote 1 if 2 out of 3 inputs are 1 • A 5 input majority voter would need 3 out 5 • A plurality voter needs a plurality (not majority)

12. How it Works, Circuit Schematic • The MIDI OX sw transforms keyboard into an electronic music keyboard. • MIDI signal is generated by the PC. • MIDI OX will send a MIDI Note On message • Cable terminated with an opto-isolator. • The CPLD will be clocked by a 4MHz crystal oscillator, from which you may have to derive local clock for sampling. • Output of CPLD drives 7 LEDs to display the note number.

13. Programming through JTAG • JTAG - Joint Test Action Group: IEEE 1149.1 standard entitled: Standard Test Access Port and Boundary-Scan Architecture • test access ports used for testing printed circuit boards (and chips) using boundary scan. • Used also for programming embedded devices. • Most FPGAs, PLDs are programmed via a JTAG port. • JTAG ports commonly available in ICs • Boundary scan, scan chains, mbist, logic bist connected • Chips chained together with Jtag signals and connected to main JTAG interface on PCB

14. Design in Verilog • A quick overview provided next Lecture • Focus is on methodology for proper design and coding

15. More Details • Please consult course website • Also check deliverables for the Lab in the Lab review document • Next • Practical advise and demo video by the UGAs