Echelon I/O Model Reference for Smart Transceivers and Neuron Chips - Manual (Page 162)

152 Timer/Counter Input Models
read input_value = 4, reset read, reset
t
ret
t
fin
READ
TIMER/
COUNTER
FLAG AND
EVENT
REGISTER
CLEAR FLAG
END OF
io_in()
START OF
io_in()
mux
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 57. Totalcount Input and Timing
Table 57. Totalcount Input Latency Values for Series 3100 Devices
Symbol Description Typical at 10 MHz
t
fin
Function call to input sample 92 μs
t
ret
Return from function 61 μs
Programming Considerations
For totalcount input, the data type of return_value for the io_in( ) function is an
unsigned long.
The minimum duration for a high or low input signal for this I/O object is 50 ns
for a Series 3100 device with a 40 MHz input clock, or 12.5 ns for a Series 5000
device with an 80 MHz system clock. This value scales inversely with the input
clock speed.