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D figure 27, 78 sh – Echelon I/O Model Reference for Smart Transceivers and Neuron Chips User Manual

Page 88

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78

Serial I/O Models

DATA OUT

Active clock edge assumed to be positive in the above diagram.

OUTPUT

CLOCK

END OF

io_in()

START OF

io_in()

t

setup

t

fin

t

aet

t

tae

t

ret

Figure 27. Bitshift Output Timing

Table 31. Bitshift Output Latency Values for Series 3100 Devices

Symbol

Description

Typical at 10 MHz

t

fin

Function call to first data out stable

16-bit shift count
1-bit shift count

185.3 μs
337.6 μs

t

ret

Return from function

10.8 μs

t

setup

Data out stable to active clock edge
15 kbps bit rate

10 kbps bit rate

1 kbps bit rate


10.8 μs

10.8 μs

10.8 μs

t

aet

Active clock edge to next clock

transition
15 kbps bit rate

10 kbps bit rate

1 kbps bit rate


10.2 μs

42 μs

939.5 μs

t

tae

Clock transition to next active clock

edge
15 kbps bit rate

10 kbps bit rate
1 kbps bit rate


34.8 μs

34.8 μs
34.8 μs

f

Clock frequency = 1/(t

aet

+ t

tae

)

15 kbps bit rate

10 kbps bit rate

1 kbps bit rate


22 kHz

13 kHz

1.02 kHz