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Programming considerations, Figure 59 and figure 60 – Echelon I/O Model Reference for Smart Transceivers and Neuron Chips User Manual

Page 170

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Timer/Counter Output Models

System Clock

Divide Chain

Timer/Counter 1

Timer/Counter 2

IO10

IO9

IO8

IO0

IO1
IO2

IO3
IO4

IO5
IO6

IO7

High Current Sink Drivers

IO11

Figure 59. Frequency Output

END

OF io_out()

t

ret

NEW OUTPUT

APPEARS ON PIN

HARDWARE

UPDATED

INTERNALLY

t

fout

START

OF io_out()

TIME

FREQUENCY

OUTPUT

ONE CYCLE

Figure 60. Frequency Output Timing

Table 59. Frequency Output Latency Values for Series 3100 Devices

Symbol

Description

Typical at 10 MHz

t

fout

Function call to output update

96 μs

t

ret

Return from function

13 μs

Programming Considerations

For frequency output, the data type of output_value for io_out( ) is an unsigned

long. An output_value of 0 forces the output signal to a low state (unless the
invert keyword is used in the declaration).