Serial interface com1

Please forward this error screen to sharedip-1071801236. Please forward this error screen to sharedip-1071801236. SPI devices communicate in serial interface com1 duplex mode using a master-slave architecture with a single master.

The master device originates the frame for reading and writing. Sometimes SPI is called a four-wire serial bus, contrasting with three-, two-, and one-wire serial buses. Slave Select is the same functionality as chip select and is used instead of an addressing concept. Pin names are always capitalized as in Slave Select, Serial Clock, and Master Output Slave Input. The SPI bus can operate with a single master device and with one or more slave devices. If a single slave device is used, the SS pin may be fixed to logic low if the slave permits it.

Some slaves require a falling edge of the chip select signal to initiate an action. To begin communication, the bus master configures the clock, using a frequency supported by the slave device, typically up to a few MHz. The master then selects the slave device with a logic level 0 on the select line. If a waiting period is required, such as for an analog-to-digital conversion, the master must wait for at least that period of time before issuing clock cycles.

During each SPI clock cycle, a full duplex data transmission occurs. The master sends a bit on the MOSI line and the slave reads it, while the slave sends a bit on the MISO line and the master reads it. This sequence is maintained even when only one-directional data transfer is intended. Data is usually shifted out with the most-significant bit first. On the clock edge, both master and slave shift out a bit and output it on the transmission line to the counterpart.