CY8C28xxx PSoC Programmable System-on-Chip TRM, Document No. 001-52594 Rev. *G
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28.5.2
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 eight and 16 clocks, respec-
tively, minus the input latency of three (count of 4 and 12 correspond to 5 and 13 clocks).
Figure 28-6. Basic Input/Output Timing
28.5.3
Status Timing
illustrates the interrupt timing for Byte Com-
plete, which occurs on the positive edge of the ninth clock
(byte + ACK/NAK) in Transmit mode and on the positive
edge of the eighth clock in Receive mode. There is a maxi-
mum of three cycles of latency, due to the input synchro-
nizer/filter circuit. As shown, the interrupt occurs on the
clock following a valid SCL positive edge input transition
(after the synchronizers). The Address bit is set with the
same timing, but only after a slave address has been
received. The LRB (Last Received Bit) status is also set with
the same timing, but only on the ninth bit after a transmitted
byte.
Figure 28-7. Byte Complete, Address, LRB Timing
shows the timing for Stop Status. This bit is set
(and the interrupt occurs) two clocks after the synchronized
and filtered SDA line transitions to a ‘1’, when the SCL line is
high.
Figure 28-8. Stop Status and Interrupt Timing
illustrates the timing for bus error interrupts. Bus
Error status (and Interrupt) occurs one cycle after the inter-
nal Start or Stop Detect (two cycles after the filtered and
synced SDA input transition).
SCL
SCL_IN
CLOCK
SDA_OUT
CLK CTR
N
1
2
N
0
1
2
N
0
0
SHIFT
SDA_IN
LOST ARB
STATUS
. . .
. . .
. . .
. . .
. . .
. . .
. . .
. . .
. . .
. . .
. . .
. . .
. . .
. . .
3 Cycles
Latency
CLOCK
Transmit: Ninth positive edge SCL
Receive: Eighth positive edge SCL
SCL
SCL_IN
(Synchronized)
IRQ
Max
CLOCK
SCL
SDA_IN
(Synchronized)
STOP IRQ
and STATUS
SDA
STOP DETECT
Содержание CY8C28 series
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Страница 85: ...84 CY8C28xxx PSoC Programmable System on Chip TRM Document No 001 52594 Rev G Internal Main Oscillator IMO ...
Страница 93: ...92 CY8C28xxx PSoC Programmable System on Chip TRM Document No 001 52594 Rev G External Crystal Oscillator ECO ...
Страница 97: ...96 CY8C28xxx PSoC Programmable System on Chip TRM Document No 001 52594 Rev G Phase Locked Loop PLL ...
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Страница 425: ...424 CY8C28xxx PSoC Programmable System on Chip TRM Document No 001 52594 Rev G Analog Reference ...
Страница 461: ...460 CY8C28xxx PSoC Programmable System on Chip TRM Document No 001 52594 Rev G Two Column Limited Analog System ...
Страница 477: ...476 CY8C28xxx PSoC Programmable System on Chip TRM Document No 001 52594 Rev G Digital Clocks ...
Страница 483: ...482 CY8C28xxx PSoC Programmable System on Chip TRM Document No 001 52594 Rev G Multiply Accumulate MAC ...
Страница 513: ...512 CY8C28xxx PSoC Programmable System on Chip TRM Document No 001 52594 Rev G Internal Voltage Reference ...
Страница 523: ...522 CY8C28xxx PSoC Programmable System on Chip TRM Document No 001 52594 Rev G Switch Mode Pump SMP ...
Страница 533: ...532 CY8C28xxx PSoC Programmable System on Chip TRM Document No 001 52594 Rev G I O Analog Multiplexer ...
Страница 537: ...536 CY8C28xxx PSoC Programmable System on Chip TRM Document No 001 52594 Rev G Real Time Clock RTC ...
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