ST25R3910 datasheet(20/65 Pages) STMICROELECTRONICS

20 / 65 page

Functional overview

ST25R3910

20/65

DocID029768 Rev 2

A SEN low pulse has to be sent after register data has been transferred in order to indicate

the end of the Read command and to prepare the Interface to the next command control

byte.

In case the register on defined address does not exist all 0 data is sent to SDATAO.

Figure 7 is an example for reading of single byte.

Figure 7. SPI communication: reading a single byte

Loading transmitting data into FIFO

Loading the transmitting data into the FIFO is similar to writing data into an addressable

registers. Difference is that in case of loading more bytes all bytes go to the FIFO. SPI

operation mode bits 10 indicate FIFO operations. In case of loading transmitting data into

FIFO all bits <C5 – C0> are set to 0. Then a bit-stream, the data to be sent (1 to 32 bytes),

can be transferred. In case the command is terminated by putting SEN low before a packet

of 8 bits (one byte) is sent, writing of that particular byte in FIFO is not performed.

Figure 8 shows how to load the Transmitting Data into the FIFO.

ST25R3910 Datasheet(PDF) 20 Page - STMicroelectronics