2000 Microchip Technology Inc.
DS30289B-page 259
PIC17C7XX
FIGURE 20-18:
I2C BUS DATA TIMING
TABLE 20-13: I2C BUS DATA REQUIREMENTS
Param
No.
Sym
Characteristic
Min
Max
Units
Conditions
100
Thigh
Clock high time
100 kHz mode
2(TOSC)(BRG + 1)
—
ms
400 kHz mode
2(TOSC)(BRG + 1)
—
ms
1 MHz mode(1)
2(TOSC)(BRG + 1)
—
ms
101
Tlow
Clock low time
100 kHz mode
2(TOSC)(BRG + 1)
—
ms
400 kHz mode
2(TOSC)(BRG + 1)
—
ms
1 MHz mode(1)
2(TOSC)(BRG + 1)
—
ms
102
Tr
SDA and SCL rise time
100 kHz mode
—
1000
ns
Cb is specified to be from
10 to 400 pF
400 kHz mode
20 + 0.1Cb
300
ns
1 MHz mode(1)
—
300
ns
103
Tf
SDA and SCL fall time
100 kHz mode
—
300
ns
Cb is specified to be from
10 to 400 pF
400 kHz mode
20 + 0.1Cb
300
ns
1 MHz mode(1)
—
10
ns
90
Tsu:sta
START condition setup
time
100 kHz mode
2(TOSC)(BRG + 1)
—
ms
Only relevant for Repeated
Start condition
400 kHz mode
2(TOSC)(BRG + 1)
—
ms
1 MHz mode(1)
2(TOSC)(BRG + 1)
—
ms
91
Thd:sta
START condition hold
time
100 kHz mode
2(TOSC)(BRG + 1)
—
ms
After this period, the first
clock pulse is generated
400 kHz mode
2(TOSC)(BRG + 1)
—
ms
1 MHz mode(1)
2(TOSC)(BRG + 1)
—
ms
106
Thd:dat
Data input hold time
100 kHz mode
0
—
ns
400 kHz mode
0
0.9
ms
1 MHz mode(1)
0
—
ns
107
Tsu:dat
Data input setup time
100 kHz mode
250
—
ns
(Note 2)
400 kHz mode
100
—
ns
1 MHz mode(1)
100
—
ns
92
Tsu:sto
STOP condition
setup time
100 kHz mode
2(TOSC)(BRG + 1)
—
ms
400 kHz mode
2(TOSC)(BRG + 1)
—
ms
1 MHz mode(1)
2(TOSC)(BRG + 1)
—
ms
109
Taa
Output valid from clock
100 kHz mode
—
3500
ns
400 kHz mode
—
1000
ns
1 MHz mode(1)
—
400
ns
Note
1:
Maximum pin capacitance = 10 pF for all I2C pins.
2: A fast mode (400 KHz) I2C bus device can be used in a standard mode I2C bus system, but the parameter # 107
≥ 250 ns
must then be met. This will automatically be the case if the device does not stretch the LOW period of the SCL signal. If
such a device does stretch the LOW period of the SCL signal, it must output the next data bit to the SDA line.
Parameter #102 + #107 = 1000 + 250 = 1250 ns (for 100 kHz mode) before the SCL line is released.
3: Cb is specified to be from 10-400pF. The minimum specifications are characterized with Cb=10pF. The rise time spec (tr)
is characterized with Rp=Rp min. The minimum fall time specification (tf) is characterized with Cb=10pF,and Rp=Rp max.
These are only valid for fast mode operation (VDD=4.5-5.5V) and where the SPM bit (SSPSTAT<7>) =1.)
4: Max specifications for these parameters are valid for falling edge only. Specs are characterized with Rp=Rp min and
Cb=400pF for standard mode, 200pF for fast mode, and 10pF for 1MHz mode.
Note:
90
91
92
100
101
103
106
107
109
110
102
SCL
SDA
In
SDA
Out