SX1441EVK Semtech, SX1441EVK Datasheet - Page 47

• Manufacturer Part Number: SX1441EVK
• Description: KIT DEV FOR SX1441
• Manufacturer: Semtech
• Series: EasyBlue™r
• Type: Bluetoothr

Specifications of SX1441EVK

• For Use With/related Products: SX1441
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Contents: -
• Other names: SX1441DVK; SX1441DVK

Personal Area Network
3.11.3 Operation
The peripheral operates in two modes: SPI and GPIO. The mode is selected by the SpiEnable bit of register
RegSpiCtrl. Selecting the SPI mode only affects the pins SCK, MOSI, MISO, and NSS[0]. The pins NSS[4:1] are
always configured as GPIO.
In SPI mode, SCK is the serial clock. It is generated by the chip in master mode and its frequency is chosen by the
bit field BaudRate of RegSpiCtrl as described in Table 75. In master mode, SpiMaster set to 1, the SX1441 is the
master. In slave mode, SpiMaster set to 0, the master should always limit the frequency of SCK to ckRCext/2).
The Figure 20 shows how to connect devices to the SPI interface. The slave connected to NSS[0] is the boot
device. The program is read from it at reset. Others slaves may be connected as described in Figure 20.
The bit ClearCounter of RegSpiCtrl may be used if the synchronization with a slave is lost, to re-initialize the
communication. The SpiRxFull flag of RegSpiStatus is used as an interrupt source in the interrupt controller
block.
The Figure 21 shows the timing diagrams for a SPI transmission with a clock phase equal to 0 (the active state of
the serial clock SCK signal occurs on the 2
The Figure 22 shows the timing diagrams for a SPI transmission with a clock phase equal to 1 (the active state of
the serial clock SCK signal occurs on the 1
© Semtech 2006
SX1441
Figure 21 - SPI transmission format with a clock phase equal to 0
NSS[0]
NSS[1]
MOSI
MISO
SCK
Figure 20 - Connecting SPI devices
nd
st
half of the SCK cycle).
half of the SCK cycle).
47
SCK
SI
SO
SCK
SI
SO
SS_n
SS_n
Boot flash
Other SPI
device
SX1441 – Bluetooth® 1.2 SoC
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Data Sheet