[sdiy] MIDI Inter-message gap

[Scott Gravenhorst]

"David J. Hughes" <hughes_david_j at btopenworld.com> wrote:
>Hello,
>
>I'm looking for a value for the minimum gap between MIDI messages but can't
>find anything in the specifications I have.
>
>Can anyone help with a value?

Interesting question, but I don't believe that there is a spec for that.  AFAIK, message
bytes can be nut-to-butt.

I'm curious, why is that important?

I've written several MIDI receiver systems (in an FPGA MCU), I've never had to deal with
that at all.  The systems are interrupt driven using an MCU running fast enough (25 MIPS)
that I've not had problems with an interrupt occurring during a previous interrupt's
service by the ISR.  My controller is _only_ a controller, i.e., it merely sets bits and
values that the synth hardware use to make the sounds.  I can see where this might be a
concern when using an MCU to both receive MIDI data and to make sound...  Maybe, but I
would think this would more relate to a slow microprocessor rather than requiring a gap
between messages.  A natural gap is the stop bit of the last byte of a message, but
that's just part of the serial protocol and not demanded by the MIDI spec itself.

-- ScottG

-------------------------------------------------------------

-- Scott Gravenhorst
-- GateMan-III - FPGA Based Monophonic MIDI Synthesizer with SVF
-- PolyDaWG/8 - FPGA Based 8 Voice Polyphonic MIDI Synthesizer
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-- When the going gets tough, the tough use the command line.