NuMicro® NUC029LEE/NUC029SEE
32-bit Arm
®
Cortex
®
-M0 Microcontroller
Aug, 2018
Page
393
of
497
Rev 1.00
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UC029
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CHN
ICA
L R
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F
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NC
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M
A
NU
A
L
I2Cn_SDA
I2Cn_SCL
Data line stable;
data valid
Change of data
allowed
Figure 6.14-5 Bit Transfer on the I
2
C Bus
I2Cn_SDA
(data output
by transmitter)
I2Cn_SCL
(from master)
START
condition
acknowlegde
I2Cn_SDA
(data output
by receiver)
S
1
2
8
9
Clock pulse for
acknowledgement
not acknowlegde
Figure 6.14-6 Acknowledge on the I
2
C Bus
6.14.5.1.5
Data transfer on the I
2
C bus
The following figure shows a master transmits data to slave. A master addresses a slave with a 7-
bit address and 1-bit write index to denote that the master wants to transmit data to the slave. The
master keeps transmitting data after the slave returns acknowledge to the master
.
A = acknowledge (I2Cn_SDA low)
A = not acknowledge (I2Cn_SDA high)
S = START condition
P = STOP condition
‘0’ : write
S
SLAVE ADDRESS
R/W
A
DATA
A
DATA
A/A
P
from master to slave
from slave to master
data transfer
(n bytes + acknowlegde)
Figure 6.14-7 Master Transmits Data to Slave
The following figure shows a master read data from slave. A master addresses a slave with a 7-
bit address and 1-bit read index to denote that the master wants to read data from the slave. The