Echelon I/O Model Reference for Smart Transceivers and Neuron Chips - Manual (Page 145)

I/O Model Reference 135
This I/O model can be used with an off-the-shelf infrared encoder/decoder chip
that uses the NEC IR protocol to quickly develop an infrared interface to a
Neuron Chip or Smart Transceiver. You can also use the edgelog input model for
this purpose, but your application program will likely require more code.
Timer/Counter 1
Timer/Counter 2
IO10
IO9
IO8
IO0
IO1
IO2
IO3
IO4
IO5
IO6
IO7
mux
Input
Data Stream
IO11
INPUT
(IO0 TO IO7)
TIME
START OF
io_in()
END OF
io_in()
t
ret t
fin
t
win (1 BIT)
Figure 51. Infrared Input and Timing
Table 51. Infrared Input Latency Values for Series 3100 Devices
Symbol Description Minimum Typical Maximum
t
fin
Function call to start of input sampling — 82.2 μs —
t
ret
End of last valid bit to function return max-
period
max-
period
—
t
win
Minimum input period width — 93 μs —
Note: max-period is the timeout period passed to the function at the time of the call.
Programming Considerations
For infrared input, the io_in( ) function requires, in addition to the io-object-
name , four arguments:
• A pointer to a data buffer in which the series of data bits are stored