Preliminary testebench specification

Connect I/O of conv-ttl-xxx board:
    - Connect Chx front - Send n pulses
    - Connect Chy rear - Send m pulses
    - Connect inverter channel to a signal
    - Connect RTM lines to pattern (Eg: conv-ttl-rs485-rtm-db9)
   

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* Check output ports:
    - Check chx front AND rear outputs correspond to front-input
    - Check chy front AND rear outputs correspond to rear-input
    - Check output channel is exactly the inverted version of the input 
    -Check all LEDs blink correctly

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Implementing I2C master, scheck following:

*Check pulse counters"
    - Check pulse counters show correct values for chx (front n pulses, rear 0) 
        and chy (front 0 pulses, rear m)
    - Check counters roll-over when max value reached
    - Check counters can be reset remotely

*Check switches:
    - Activate "ttl-bar" mode
    - Input ttl pulses on chx, check output is inverted
    - Activate glitch filter
        - Send pulse shorter than 50ns -> check pulse is ignored
        - Send pulse longer than 50ns -> check output is synched to clock

* Check RTM line register is correct        

* Check correct flagging of errors:
    - I2C error (see manual)
* Check time stamping    
    - Check pulse timetag in last timestamp register
    
    