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
Summary of Contents for PSoC CY8C23533
Page 4: ...Contents Overview 4 Document 001 20559 Rev D Section G Glossary 385 Index 401 ...
Page 16: ...Contents Overview 16 Document 001 20559 Rev D ...
Page 24: ...24 Document 001 20559 Rev D Section A Overview ...
Page 30: ...30 Document 001 20559 Rev D Pin Information ...
Page 54: ...54 Document 001 20559 Rev D Supervisory ROM SROM ...
Page 60: ...60 Document 001 20559 Rev D RAM Paging ...
Page 68: ...68 Document 001 20559 Rev D Interrupt Controller ...
Page 76: ...12 Document 001 20559 Rev D General Purpose IO GPIO ...
Page 82: ...18 Document 001 20559 Rev D Internal Main Oscillator IMO ...
Page 84: ...20 Document 001 20559 Rev D Internal Low Speed Oscillator ILO ...
Page 90: ...26 Document 001 20559 Rev D External Crystal Oscillator ECO ...
Page 94: ...30 Document 001 20559 Rev D Phase Locked Loop PLL ...
Page 106: ...42 Document 001 20559 Rev D Sleep and Watchdog ...
Page 228: ...164 Document 001 20559 Rev D Section D Digital System ...
Page 234: ...170 Document 001 20559 Rev D Array Digital Interconnect ADI ...
Page 278: ...214 Document 001 20559 Rev D Digital Blocks ...
Page 296: ...232 Document 001 20559 Rev D Analog Interface ...
Page 304: ...240 Document 001 20559 Rev D Analog Array ...
Page 308: ...244 Document 001 20559 Rev D Analog Input Configuration ...
Page 312: ...248 Document 001 20559 Rev D Analog Reference ...
Page 338: ...274 Document 001 20559 Rev D Section F System Resources ...
Page 354: ...290 Document 001 20559 Rev D Multiply Accumulate MAC ...
Page 374: ...310 Document 001 20559 Rev D I2C ...
Page 400: ...336 Document 001 20559 Rev D Section G Glossary ...