PIC16F87XA
DS39582B-page 192
2003 Microchip Technology Inc.
TABLE 17-11: I2C BUS DATA REQUIREMENTS
Param
No.
Sym
Characteristic
Min
Max
Units
Conditions
100
THIGH
Clock High Time
100 kHz mode
4.0
鈥�
s
400 kHz mode
0.6
鈥�
s
SSP Module
0.5 TCY
鈥�
101
TLOW
Clock Low Time
100 kHz mode
4.7
鈥�
s
400 kHz mode
1.3
鈥�
s
SSP Module
0.5 TCY
鈥�
102
TR
SDA and SCL Rise
Time
100 kHz mode
鈥�
1000
ns
400 kHz mode
20 + 0.1 CB
300
ns
Cb is specified to be from 10 to
400 pF
103
TF
SDA and SCL Fall
Time
100 kHz mode
鈥�
300
ns
400 kHz mode
20 + 0.1 CB
300
ns
CB is specified to be from 10 to
400 pF
90
TSU:STA
Start Condition Setup
Time
100 kHz mode
4.7
鈥�
s
Only relevant for Repeated Start
condition
400 kHz mode
0.6
鈥�
s
91
THD:STA
Start Condition Hold
Time
100 kHz mode
4.0
鈥�
s
After this period, the first clock
pulse is generated
400 kHz mode
0.6
鈥�
s
106
THD:DAT
Data Input Hold Time
100 kHz mode
0
鈥�
ns
400 kHz mode
0
0.9
s
107
TSU:DAT
Data Input Setup Time 100 kHz mode
250
鈥�
ns
(Note 2)
400 kHz mode
100
鈥�
ns
92
TSU:STO
Stop Condition Setup
Time
100 kHz mode
4.7
鈥�
s
400 kHz mode
0.6
鈥�
s
109
TAA
Output Valid from
Clock
100 kHz mode
鈥�
3500
ns
(Note 1)
400 kHz mode
鈥�
ns
110
TBUF
Bus Free Time
100 kHz mode
4.7
鈥�
s
Time the bus must be free before
a new transmission can start
400 kHz mode
1.3
鈥�
s
CB
Bus Capacitive Loading
鈥�
400
pF
Note
1:
As a transmitter, the device must provide this internal minimum delay time to bridge the undefined region (min. 300 ns)
of the falling edge of SCL to avoid unintended generation of Start or Stop conditions.
2:
A fast mode (400 kHz) I2C bus device can be used in a standard mode (100 kHz) I2C bus system, but the requirement
that, TSU:DAT
鈮� 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, TR MAX. + TSU:DAT = 1000 + 250 = 1250 ns (according to the standard mode I2C bus specification),
before the SCL line is released.
