Atmel SAM4S-XPLD Atmel ATSAM4S-XPLD ATSAM4S-XPLD Scheda Tecnica

 605

SAM4S [DATASHEET]

11100E–ATARM–24-Jul-13

 shows Transmit Data Register Empty (TDRE), Receive Data Register (RDRF) and Transmission Register

Empty (TXEMPTY) status flags behavior within the SPI_SR (Status Register) during an 8-bit data transfer in fixed mode
and no Peripheral Data Controller involved.

 shows Transmission Register Empty (TXEMPTY), End of RX buffer (ENDRX), End of TX buffer (ENDTX),

RX Buffer Full (RXBUFF) and TX Buffer Empty (TXBUFE) status flags behavior within the SPI_SR (Status Register)
during an 8-bit data transfer in fixed mode with the Peripheral Data Controller involved. The PDC is programmed to
transfer and receive three data. The next pointer and counter are not used. The RDRF and TDRE are not shown
because these flags are managed by the PDC when using the PDC.

6

SPCK

MOSI

(from master)

MISO

(from slave)

NPCS0

MSB

MSB

LSB

LSB

6

6

5

5

4

4

3

3

2

2

1

1

1

2

3

4

5

7

8

6

RDRF

TDRE

TXEMPTY

Write in

SPI_TDR

RDR read

shift register empty