MK41T56N00 Просмотр технического описания (PDF) - STMicroelectronics
Номер в каталоге
Компоненты Описание
производитель
MK41T56N00 Datasheet PDF : 15 Pages
| |||
MK41T56, MKI41T56
Table 10. AC Characteristics
(TA = 0 to 70°C or –40 to 85°C; VCC = 4.5V to 5.5V)
Symbol
Parameter
Min
Max
Unit
fSCL
SCL Clock Frequency
tLOW
Clock Low Period
0
100
kHz
4.7
µs
tHIGH
tR
Clock High Period
SDA and SCL Rise Time
4
µs
1
µs
tF
SDA and SCL Fall Time
300
ns
tHD:STA
START Condition Hold Time
(after this period the first clock pulse is generated)
4
µs
tSU:STA
tSU:DAT (1)
tHD:DAT
START Condition Setup Time
(only relevant for a repeated start condition)
Data Setup Time
Data Hold Time
4.7
µs
250
ns
0
µs
tSU:STO STOP Condition Setup Time
4.7
µs
tBUF
Time the bus must be free before a new transmission can start
4.7
µs
tI
Noise suppression time constant at SCL and SDA input
0.25
1
µs
Note: 1. Transmitter must internally provide a hold time to bridge the undefined region (300ns max.) of the falling edge of SCL.
2-WIRE BUS CHARACTERISTICS (cont’d)
Accordingly, the following bus conditions have
been defined:
Bus not busy. Both data and clock lines remain
High.
Start data transfer. A change in the state of the
data line, from High to Low, while the clock is High,
defines the START condition.
Stop data transfer. A change in the state of the
data line, from Low to High, while the clock is High,
defines the STOP condition.
Data valid. The state of the data line represents
valid data when after a start condition, the data line
is stable for the duration of the High period of the
clock signal. The data on the line may be changed
during the Low period of the clock signal. There is
one clock pulse per bit of data.
Each data transfer is initiated with a start condition
and terminated with a stop condition. The number
of data bytes transferred between the start and stop
conditions is not limited. The information is trans-
mitted byte-wide and each receiver acknowledges
with a ninth bit.
By definition, a device that gives out a message is
called "transmitter", the receiving device that gets
the message is called "receiver". The device that
controls the message is called "master". The de-
vices that are controlled by the master are called
"slaves".
Acknowledge. Each byte of eight bits is followed
by one acknowledge bit. This acknowledge bit is a
low level put on the bus by the receiver, whereas
the master generates an extra acknowledge re-
lated clock pulse.
A slave receiver which is addressed is obliged to
generate an acknowledge after the reception of
each byte. Also, a master receiver must generate
an acknowledge after the reception of each byte
that has been clocked out of the slave transmitter.
The device that acknowledges has to pull down the
SDA line during the acknowledge clock pulse in
such a way that the SDA line is a stable Low during
the High period of the acknowledge related clock
pulse. Of course, setup and hold times must be
taken into account. A master receiver must signal
an end-of-data to the slave transmitter by not gen-
erating an acknowledge on the last byte that has
been clocked out of the slave. In this case, the
transmitter must leave the data line High to enable
the master to generate the STOP condition.
6/15
Share Link: 