Echelon I/O Model Reference for Smart Transceivers and Neuron Chips - Manual (Page 179)

I/O Model Reference 169
Output on page 190 for the frequency of the waveform for various clock select
values. This model is useful for external counting devices that can accumulate
pulse trains, such as stepper motors (see Figure 63).
The io_out( ) function does not return until all output pulses have been produced.
t
fout
is the time from function call to first output pulse. Therefore, the calling of
this function ties up the application processor for a period of N x (pulse period) +
t
fout
+ t
ret
, where N is the number of specified output pulses.
The polarity of the output depends on whether the invert option is used in the
declaration of the function block. The default is low with high pulses.
Figure 63. Pulsecount Output and Timing
Table 63. Pulsecount Output Latency Values for Series 3100 Devices
Symbol Description Typical at 10 MHz
t
fout
Function call to first active output pulse
edge 115 μs
t
ret
Return from function 5 μs