ST25R3920 datasheet(49/152 Pages) STMICROELECTRONICS

49 / 152 page

DS13261 Rev 9

49/152

ST25R3920

Application information

151

Figure 13. SPI communication: reading a single byte

Read or write access to register space-B

To access the register space-B the register read or write SPI sequence has to be prefixed

with the byte FBh. Access to register space-B remains active until the rising edge of BSS.

Loading transmitting data into FIFO

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

registers. The SPI sequence starts with SPI operation mode bits ‘10’ to indicate a FIFO

operation followed by bits <C5:C0> set to 000000b. After the FIFO mode byte at least one

and up to 512 data bytes must be sent.

Figure 14 shows how to load the transmitting data into the FIFO.

Figure 14. SPI communication: FIFO loading

MS51646V1

SCLK rising edge

Data transferred from MCU

SCLK falling edge

Data is sampled

BSS raising

edge indicates

end of

Read mode

Two leading bits

indicate Mode

BSS

SCLK

MOSI

tristate

MISO

SCLK rising edge

Data moved from

Address A5-A0

SCLK falling edge

Data transferred to MCU

MS51647V1

SCLK rising edge

Data transferred from MCU

SCLK falling edge

Data is sampled

BSS

raising edge

indicates end

of FIFO mode

000

BSS

SCLK

MOSI

10 pattern

indicates

FIFO mode

1 to 512

bytes

Start of

paylod data

ST25R3920 Datasheet(PDF) 49 Page - STMicroelectronics

ST25R3920 Datasheet(HTML) 49 Page - STMicroelectronics

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Datasheet Download

Link URL