304
Document # 001-20559 Rev. *D
I2C
28.4
Timing Diagrams
28.4.1
Clock Generation
illustrates the I2C input clocking scheme. The SYSCLK pin is an input into a four-stage ripple divider that pro-
vides the baud rate selections. When the block is disabled, all internal state is held in a reset state. When either the Master or
Slave Enable bits in the I2C_CFG register are set, the reset is synchronously released and the clock generation is enabled.
Two taps from the
are selectable (/4, /16) from the clock rate bits in the I2C_CFG register. If any of the two
divider taps is selected, that clock is resynchronized to SYSCLK. The resulting clock is routed to all of the synchronous ele-
ments in the design.
Figure 28-4. I
2
C Input Clocking
28.4.2
Basic Input/Output Timing
illustrates basic input output timing that is valid for both 16 times sampling and 32 times sampling. For 16 times
sampling, N=4; and for 32 times sampling, N=12. N is derived from the half-bit rate sampling of 8 and 16 clocks, respectively,
minus the input latency of three (count of 4 and 12 correspond to 5 and 13 clocks).
Figure 28-5. Basic Input/Output Timing
I/O WRITE
SYSCLK
4
2
8
16
Two SYSCLKS to first block clock.
ENABLE
BLOCK RESET
RESYNC CLOCK
Default
16
SCL
SCL_IN
CLOCK
SDA_OUT
CLK CTR
N
1
2
N
0
1
2
N
0
0
SHIFT
SDA_IN
LOST ARB
STATUS
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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 ...