;
; MIDI Performance Measuring Application
;
; This is some kind of benchmark which helps to evaluate the performance
; of your MIDI interface (and computer)
;
; To get the test running you have to create a MIDI feedback loop.
;
; Examples:
; Direct Feedback: CORE1 OUT -> CORE1 IN
; Merger Feedback: CORE1 OUT -> CORE2 IN -> CORE2 OUT -> CORE1 IN
; Computer Feedback: CORE1 OUT -> PC MIDI IN -> MIDI-Ox -> PC MIDI OUT -> CORE1 IN
;
; A MIDI controller event will be sent and should be received "immediately"
; is measured with timer3, prescaler 1:8 - this means, that the counter
; result has to be multiplied by 8 and 100 nS (@40 MHz) to get the
; absolute delay
;
; Note that the delay is always greater than 960 uS, since this is the
; initial transfer time of a controller event
;
; The current, minimal and maximum result will be print on LCD
; To determine the jitter, calculate: (max-min) / 2
;
; IMPORTANT: remove the feedback loop before uploading a new application,
; otherwise MIOS will wait endless before rebooting the core!!!
;
; And here the results:
;
; o direct feedback:
; Min: 1218, Max: 1262 -> 0.97 mS / 1.01 mS -> +/- 0.02 mS Jitter
;
; o merger feedback (2 cores):
; Min: 1664, Max: 1735 -> 1.33 mS / 1.38 mS -> +/- 0.03 mS Jitter
;
; o RME Hammerfall DSP/Multiface, WinXP, Feedback via MIDI-Ox
; Min: 2497, Max: 2599 -> 2.00 mS / 2.07 mS -> +/- 0.04 mS Jitter
;
; o RME Hammerfall DSP/Multiface, WinXP, Feedback via Logic Audio
; Min: 2565, Max: 3820 -> 2.05 mS / 3.05 mS -> +/- 0.50 mS Jitter
;
; o MBHP_USB (WinXP Legacy Driver), Feedback via MIDI-Ox
; Min: 3320, Max: 4555 -> 2.66 mS / 3.64 mS -> +/- 0.50 mS Jitter
;
; o MBHP_USB (WinXP Legacy Driver), Feedback via Logic Audio
; Min: 3510, Max: 6291 -> 2.81 mS / 5.03 mS -> +/- 1.11 mS Jitter
;
; o MIDIsport 2x2, WinXP, Feedback via MIDI-Ox
; Min: 6219, Max: 9960 -> 4.98 mS / 7.97 mS -> +/- 1.5 mS Jitter
;
; o MIDIsport 2x2, WinXP, Feedback via Logic Audio
; Min: 7608, Max: 13446 -> 6.08 mS / 10.76 mS -> +/- 2.3 mS Jitter
Today I finally got my core well working and tested my MIDI interface which connects to a gameport of a sound card. It is based on scheme from here: http://www.borg.com/~jglatt/hardware/pc_intfc.htm. If anybody wants PCB I can put a *.brd somewhere. Results:
