Check 2 PWM Announcements Overview LED Board PWM
Check 2 - PWM • Announcements • Overview • LED Board • PWM What’s due: • Prelab • Lab
Announcements • Checkpoint 2 handout has suggestions for the lab. • Corrections to older versions of checkpoint 2: • Add lab 9 pinout. sch and lab 9 LIB file. • Wire wrap LED board • To test Mode 1, use : U: WVLIBTransmitter. exe See Readme file.
Data Path For Checkpoint 2 UART SRAM Mode 1 FSM PWM Block Switch Bank 5 ROM LED Board
Mode 1 FSM • Very simple • Wait for a header • Write 10 x 14 = 140 bytes to SRAM • Enable PWM until reset is asserted • K. I. S. S.
LED Board Protocol • LED Board Protocol Col 13 Col 12 Col 11 Col 10 Col 9 Col 8 Col 7 Col 6 Col 5 Col 4 Col 3 Col 2 Col 1 Col 0 Row 1 Row 2 Row 3 DATAOUT CLKOUT Hex row digit 14 binary Column digits • Inputs DATAOUT, CLKOUT, DISPE_H
LED Board • CLKOUT >> 19. 2 k. Hz CLKOUT DISPE_H • 8, 9, 10 MHz are good
Pulse Width Modulation LED 1 Time LED 2 Time 3
PWM Example Brightness = 4 / 31 ON OFF 0 1 2 3 4 5 5 6 7 8 9
Debugging Tips Works in sim, but not in hardware!! What now? • Run the TA bit file to verify hardware. • U: wvlibcs 150lab 9. bit • Verify on oscilloscope that clkout is glitch-free. • Use NUMLED 1 to output debugging signals such as state.
Due next week • Prelab • Complete State Transition Diagrams for entire project. • PWM and Mode 1 schematics, test scripts and waveform results. • Lab • Display image from Transmitter program • Partial credit for still image, grey-scale image
- Slides: 10