Echelon I/O Model Reference for Smart Transceivers and Neuron Chips - Manual (Page 159)

I/O Model Reference 149
A
B
read, reset read, reset read, reset read, reset
t
ret
READ
TIMER/COUNTER
FLAG AND
EVENT
REGISTER
CLEAR FLAG
END OF
io_in()
START OF
io_in()
Count + 6 counts Count – 6 counts
2 x XIN (or CLK1) Period, Ex: 200 ns @ 10MHz
(minimum time allowed
between consecutive transitions)
INPUT 1
INPUT 2
t
fin
Event Register
IO10
IO9
IO8
IO0
IO1
IO2
IO3
IO4
IO5
IO6
IO7
Optional Pull-Up Resistors for 3100 Family Devices
Event Register
Timer/Counter 2
Timer/Counter 1
IO11
Figure 55. Quadrature Input and Timing
Table 56. Quadrature Input Latency Values for Series 3100 Devices
Symbol Description Typical at 10 MHz
t
fin
Function call to input sample 90 μs
t
ret
Return from function 88 μs