Datasheet

PRELIMINARY PRODUCT SPECIFICATION
nRF24L01 Single Chip 2.4 GHz Radio Transceiver
Nordic Semiconductor ASA - Vestre Rosten 81, N-7075 Tiller, Norway - Phone [phone] - Fax [phone]
Revision: 1.2 Page 20 of 39 March 2006
writing can be terminated before all bytes in a multi-byte register has been written. In
this case the unwritten MSByte(s) will remain unchanged. E.g. the LSByte of
RX_ADDR_P0 can be modified by writing only one byte to the RX_ADDR_P0
register. The content of the status register will always be read to MISO after a high to
low transition on CSN.
Interrupt
The nRF24L01 has an active low interrupt pin (IRQ). The interrupt pin is activated
when TX_DS, RX_DR or MAX_RT is set high in status register. When MCU writes
'1' to the interrupt source, the IRQ pin will go inactive. The interrupt mask part of the
CONFIG register is used to mask out the interrupt sources that are allowed to set the
IRQ pin low. By setting one of the MASK bits high, the corresponding interrupt
source will be disabled. By default all interrupt sources are enabled.
SPI Timing
The interface supports SPI. SPI operation and timing is given in Figure 8 to Figure 10
and in Table 9 and Table 10. The device must be in one of the standby modes or
power down mode before writing to the configuration registers. In Figure 8 to Figure
10 the following notations are used:
Cn – SPI Instruction Bit
Sn – Status Register Bit
Dn – Data Bit (note: LSByte to MSByte, MSBit in each byte first)
C7 C6 C5 C4 C3 C2 C1 C0
S7 S6 S5 S4 S3 S2 S1 S0 D7 D6 D5 D4 D3 D2 D1 D0 D15 D1 4 D13 D12 D11 D10 D9 D8
CSN
SCK
MOSI
MISO
Figure 8 SPI read operation.
C7 C6 C5 C4 C3 C2 C1 C0 D7 D6 D5 D4 D3 D2 D1 D0 D15 D14 D13 D12 D11 D10 D9 D8
S7 S6 S5 S4 S3 S2 S1 S0
CSN
SCK
MOSI
MIS O
Figure 9 SPI write operation.