Document # 001-20559 Rev. *D
309
I2C
28.4.9
Master Clock Synchronization
shows the timing associated with Master Clock Synchronization. Clock synchronization is always operational,
even if it is the only master on the bus. In which case, it is synchronizing to its own clock. In the wired AND bus, an SCL out-
put of ‘0’ is seen by all masters. When the hardware asserts a ‘0’ to the output, it is immediately fed back from the PSoC
device pin to the input synchronizer for the SCL input. The counter value (depending on the sampling rate) takes into account
the worst case latency for input synchronization of three clocks, giving a net period of 8/16 clocks for both high and low time.
This results in an overall clocking rate of 16/32 clocks per bit.
In multi-master environments when the hardware outputs a ‘1’ on the SCL output, if any other master is still asserting a ‘0’, the
clock counter holds until the SCL input line matches the ‘1’ on the SCL output line. When matched, the remainder of the high
time is counted down. In this way, the master with the fastest frequency determines the high time of the clock and the master
with the lowest frequency determines the low time of the clock.
Figure 28-16. Master Clock Synchronization
SCL
SCL_IN
CLOCK
SCL_OUT
Synchronize
and Filter
0
N
3
2
1
N
Hold off counting until
the Input Clock is equal
to the Output Clock.
...
0
3
2
1
Содержание PSoC CY8C23533
Страница 4: ...Contents Overview 4 Document 001 20559 Rev D Section G Glossary 385 Index 401 ...
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Страница 30: ...30 Document 001 20559 Rev D Pin Information ...
Страница 54: ...54 Document 001 20559 Rev D Supervisory ROM SROM ...
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Страница 76: ...12 Document 001 20559 Rev D General Purpose IO GPIO ...
Страница 82: ...18 Document 001 20559 Rev D Internal Main Oscillator IMO ...
Страница 84: ...20 Document 001 20559 Rev D Internal Low Speed Oscillator ILO ...
Страница 90: ...26 Document 001 20559 Rev D External Crystal Oscillator ECO ...
Страница 94: ...30 Document 001 20559 Rev D Phase Locked Loop PLL ...
Страница 106: ...42 Document 001 20559 Rev D Sleep and Watchdog ...
Страница 228: ...164 Document 001 20559 Rev D Section D Digital System ...
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