USCI Operation: SPI Mode
20-5
Universal Serial Communication Interface, SPI Mode
20.3 USCI Operation: SPI Mode
In SPI mode, serial data is transmitted and received by multiple devices using
a shared clock provided by the master. An additional pin, UCxSTE, is provided
to enable a device to receive and transmit data and is controlled by the master.
Three or four signals are used for SPI data exchange:
-
UCxSIMO
Slave in, master out
Master mode: UCxSIMO is the data output line.
Slave mode: UCxSIMO is the data input line.
-
UCxSOMI
Slave out, master in
Master mode: UCxSOMI is the data input line.
Slave mode: UCxSOMI is the data output line.
-
UCxCLK
USCI SPI clock
Master mode: UCxCLK is an output.
Slave mode: UCxCLK is an input.
-
UCxSTE
Slave transmit enable. Used in 4-pin mode to allow multiple
masters on a single bus. Not used in 3-pin mode. Table 20−1
describes the UCxSTE operation.
Table 20−1.UCxSTE Operation
UCMODEx
UCxSTE Active State
UCxSTE
Slave
Master
01
high
0
inactive
active
01
high
1
active
inactive
10
low
0
active
inactive
10
low
1
inactive
active
Summary of Contents for MSP430x4xx Family
Page 1: ...MSP430x4xx Family 2007 Mixed Signal Products User s Guide SLAU056G ...
Page 2: ......
Page 6: ...vi ...
Page 114: ...3 76 RISC 16 Bit CPU ...
Page 304: ...5 20 FLL Clock Module ...
Page 340: ...7 8 Supply Voltage Supervisor ...
Page 348: ...8 8 16 Bit Hardware Multiplier ...
Page 372: ...9 24 32 Bit Hardware Multiplier ...
Page 400: ...10 28 DMA Controller ...
Page 428: ...13 10 Basic Timer1 ...
Page 466: ...15 24 Timer_A ...
Page 522: ...17 30 USART Peripheral Interface UART Mode ...
Page 544: ...18 22 USART Peripheral Interface SPI Mode ...
Page 672: ...23 12 Comparator_A ...
Page 692: ...24 20 LCD Controller ...
Page 746: ...26 28 ADC12 ...