Datasheet

Table Of Contents
2010 Microchip Technology Inc. DS39770C-page 389
PIC18F85J90 FAMILY
TABLE 26-21: MSSP I
2
C™ BUS DATA REQUIREMENTS
Param.
No.
Symbol Characteristic Min Max Units Conditions
100 T
HIGH Clock High
Time
100 kHz mode 2(TOSC)(BRG + 1)
400 kHz mode 2(TOSC)(BRG + 1)
1 MHz mode
(1,2)
2(TOSC)(BRG + 1)
101 TLOW Clock Low Time 100 kHz mode 2(TOSC)(BRG + 1)
400 kHz mode 2(TOSC)(BRG + 1)
1 MHz mode
(1,2)
2(TOSC)(BRG + 1)
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 + 0.1 CB 300 ns
1 MHz mode
(1,2)
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 + 0.1 CB 300 ns
1 MHz mode
(1,2)
100 ns
90 T
SU:STA Start Condition
Setup Time
100 kHz mode 2(TOSC)(BRG + 1) Only relevant for Repeated
Start condition
400 kHz mode 2(TOSC)(BRG + 1)
1 MHz mode
(1,2)
2(TOSC)(BRG + 1)
91 THD:STA Start Condition
Hold Time
100 kHz mode 2(TOSC)(BRG + 1) After this period, the first
clock pulse is generated
400 kHz mode 2(TOSC)(BRG + 1)
1 MHz mode
(1,2)
2(TOSC)(BRG + 1)
106 THD:DAT Data Input
Hold Time
100 kHz mode 0 ns
400 kHz mode 0 0.9 s
1 MHz mode
(1,2)
——ns
107 TSU:DAT Data Input
Setup Time
100 kHz mode 250 ns (Note 3)
400 kHz mode 100 ns
1 MHz mode
(1,2)
——ns
92 TSU:STO Stop Condition
Setup Time
100 kHz mode 2(TOSC)(BRG + 1)
400 kHz mode 2(TOSC)(BRG + 1)
1 MHz mode
(1,2)
2(TOSC)(BRG + 1)
109 TAA Output Valid
from Clock
100 kHz mode 3500 ns
400 kHz mode 1000 ns
1 MHz mode
(1,2)
——ns
110 TBUF Bus Free Time 100 kHz mode 4.7 s Time the bus must be free
before a new transmission
can start
400 kHz mode 1.3 s
1 MHz mode
(1,2)
——s
D102 CB Bus Capacitive Loading 400 pF
Note 1: Maximum pin capacitance = 10 pF for all I
2
C™ pins.
2: A minimum 16 MHz F
OSC is required for 1 MHz I
2
C.
3: A Fast mode I
2
C bus device can be used in a Standard mode I
2
C bus system, but 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 + parameter #107 = 1000 + 250 = 1250 ns (for 100 kHz
mode), before the SCL line is released.