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Programming considerations – Echelon I/O Model Reference for Smart Transceivers and Neuron Chips User Manual

Page 137

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I/O Model Reference

127

Timer/Counter 1

Timer/Counter 2

IO10

IO9

IO8

IO0

IO1
IO2

IO3
IO4

IO5
IO6

IO7

mux

Control Output

From
Comparator

IO11

OUTPUT

(IO0 OR IO1)

START OF

io_in_request()

END OF

io_in()

LATCHED COUNT

AVAILABLE TO

APPLICATION

START

OF io_in()

TIME

INPUT

(IO4 TO IO7)

ANALOG SWITCH
CONTROL

COMPARATOR

OUTPUT

INTEGRATOR

OUTPUT

V

thresh

t

reqo

t

fin

Figure 48. Dualslope Input and Timing

Table 49. Dualslope Input Latency Values for Series 3100 Devices

Symbol Description

Minimum

Typical

Maximum

t

reqo

io_in_request() to output toggle

75.6 μs —

t

fin

Input function call and return

82.8 μs —

Programming Considerations

For dualslope input, the data type of the control_value for the io_in_request( )
function is an unsigned long. The return value of the io_in( ) function is an

unsigned long. Both the return value for io_in( ) and the value stored at

input_value is a number biased negatively by the control_value used for the
io_in_request( ) function, and can be corrected by adding the control_value value

into it.