USCI Operation: I2C Mode
21-8
Universal Serial Communication Interface, I2C Mode
21.3.3 I
2
C Addressing Modes
The I
2
C mode supports 7-bit and 10-bit addressing modes.
7-Bit Addressing
In the 7-bit addressing format, shown in Figure 21−5, the first byte is the 7-bit
slave address and the R/W bit. The ACK bit is sent from the receiver after each
byte.
Figure 21−5. I
2
C Module 7-Bit Addressing Format
S
Slave Address
R/W
ACK
Data
ACK
Data
ACK
P
7
8
8
1
1
1
1
1
1
10-Bit Addressing
In the 10-bit addressing format, shown in Figure 21−6, the first byte is made
up of 11110b plus the two MSBs of the 10-bit slave address and the R/W bit.
The ACK bit is sent from the receiver after each byte. The next byte is the
remaining 8 bits of the 10-bit slave address, followed by the ACK bit and the
8-bit data.
Figure 21−6. I
2
C Module 10-Bit Addressing Format
S
1
Slave Address 1st byte
7
Slave Address 2nd byte
ACK
R/W
1
1
8
ACK
1
Data
8
ACK
1
P
1
1
1
1
1
0
X
X
Repeated Start Conditions
The direction of data flow on SDA can be changed by the master, without first
stopping a transfer, by issuing a repeated START condition. This is called a
RESTART. After a RESTART is issued, the slave address is again sent out with
the new data direction specified by the R/W bit. The RESTART condition is
shown in Figure 21−7.
Figure 21−7. I
2
C Module Addressing Format with Repeated START Condition
1
7
8
7
8
1
1
1
1
1
1
1
1
S
Slave Address
R/W
ACK
Data
ACK
S
Slave Address
R/W
ACK
Data
ACK
P
1
Any
Number
1
Any Number
Содержание MSP430x4xx Family
Страница 1: ...MSP430x4xx Family 2007 Mixed Signal Products User s Guide SLAU056G ...
Страница 2: ......
Страница 6: ...vi ...
Страница 114: ...3 76 RISC 16 Bit CPU ...
Страница 304: ...5 20 FLL Clock Module ...
Страница 340: ...7 8 Supply Voltage Supervisor ...
Страница 348: ...8 8 16 Bit Hardware Multiplier ...
Страница 372: ...9 24 32 Bit Hardware Multiplier ...
Страница 400: ...10 28 DMA Controller ...
Страница 428: ...13 10 Basic Timer1 ...
Страница 466: ...15 24 Timer_A ...
Страница 522: ...17 30 USART Peripheral Interface UART Mode ...
Страница 544: ...18 22 USART Peripheral Interface SPI Mode ...
Страница 672: ...23 12 Comparator_A ...
Страница 692: ...24 20 LCD Controller ...
Страница 746: ...26 28 ADC12 ...