
PIC18F2480/2580/4480/4580
DS39637A-page 446
Preliminary
2004 Microchip Technology Inc.
TABLE 27-19: I
2
C BUS DATA REQUIREMENTS (SLAVE MODE)
Param.
No.
Symbol
Characteristic
Min
Max
Units
Conditions
100
T
HIGH
Clock High Time
100 kHz mode
4.0
—
μ
s
PIC18FXXXX must operate at
a minimum of 1.5 MHz
PIC18FXXXX must operate at
a minimum of 10 MHz
400 kHz mode
0.6
—
μ
s
SSP Module
100 kHz mode
1.5 T
CY
4.7
—
—
101
T
LOW
Clock Low Time
μ
s
PIC18FXXXX must operate at
a minimum of 1.5 MHz
PIC18FXXXX must operate at
a minimum of 10 MHz
400 kHz mode
1.3
—
μ
s
SSP Module
100 kHz mode
400 kHz mode
1.5 T
CY
—
20 + 0.1 C
B
—
102
T
R
SDA and SCL Rise
Time
1000
300
ns
ns
C
B
is specified to be from
10 to 400 pF
103
T
F
SDA and SCL Fall
Time
100 kHz mode
400 kHz mode
—
300
300
ns
ns
20 + 0.1 C
B
C
B
is specified to be from
10 to 400 pF
Only relevant for Repeated
Start condition
90
T
SU
:
STA
Start Condition Setup
Time
100 kHz mode
400 kHz mode
100 kHz mode
400 kHz mode
100 kHz mode
400 kHz mode
4.7
0.6
4.0
0.6
0
0
250
100
4.7
0.6
—
—
4.7
1.3
—
—
—
—
—
0.9
—
—
—
—
3500
—
—
—
μ
s
μ
s
μ
s
μ
s
ns
μ
s
ns
ns
μ
s
μ
s
ns
ns
μ
s
μ
s
91
T
HD
:
STA
Start Condition Hold
Time
After this period, the first clock
pulse is generated
106
T
HD
:
DAT
Data Input Hold Time
107
T
SU
:
DAT
Data Input Setup Time 100 kHz mode
(Note 2)
400 kHz mode
100 kHz mode
400 kHz mode
100 kHz mode
400 kHz mode
100 kHz mode
400 kHz mode
92
T
SU
:
STO
Stop Condition Setup
Time
109
T
AA
Output Valid from
Clock
(Note 1)
110
T
BUF
Bus Free Time
Time the bus must be free
before a new transmission can
start
D102
Note
C
B
Bus Capacitive Loading
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.
A Fast mode I
2
C bus device can be used in a Standard mode I
2
C bus system, but the requirement T
SU
:
DAT
≥
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,
T
R
max. + T
SU
:
DAT
= 1000 + 250 = 1250 ns (according to the Standard mode I
2
C bus specification), before the SCL line
is released.
—
400
pF
1:
2: