SX1441EVK Semtech, SX1441EVK Datasheet - Page 55

• 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
3.12.8 Flow Control
When automatic flow control is activated (UartFlowCtrl = 1), the transmission stops as soon as signal CTS is
raised. It transmits otherwise as long as data are available for transmission.
On the receiver side, the RTS signal will automatically be driven high as the antepenultimate byte of the receive
FIFO is filled. It is driven low again as the receive FIFO is emptied (RtsLevelMode = 1) or as only two bytes are
left in the FIFO (RtsLevelMode = 0).
By connecting two devices as shown in Figure 27, transmission overruns are avoided as a device will automatically
stop transmitting as the other one - receive FIFO - gets full.
If flow control is disabled, pins CTS and RTS can be used as digital input/output ports.
Setting bit RtsMonitorMode to 1 will automatically raise the RTS signal as the chip enters the debug mode. This
bit should be set by default to prevent loss of data.
3.12.9 Software Hints
The transmission and reception software can be driven by interruption or by polling the status bits.
3.12.9.1
Initialize RegUartFifoBaud and RegUartFifoCtrl with the communication parameters (for example 8-bit word
length, odd parity, 115200 bauds, enable UART transmission)
Write 8 bytes into the transmit FIFO (RegUartFifoTx)
Wait until UartTxFifoEmpty in RegUartFifoTxSta is set
Jump to 2) to write the next 8 bytes if the message is not finished
End of transmission
3.12.9.2
Initialize RegUartFifoBaud and RegUartFifoCtrl with the communication parameters (for example 8-bit word
length, odd parity, 115200 bauds, enable UART transmission)
© Semtech 2006
read of RegUartFifoRx
UartRxFifoDataReady
IrqRxComp and RTS
IrqRxDataReady
UartRxFifoFull
UartRxBusy
shift enable
Transmission with Polling
Transmission with Interrupt
RxFifo(3)
RxFifo(2)
RxFifo(1)
RxFifo(0)
RTS
Rx
1
2
start
Figure 26 – Uart reception timing diagram with FIFO depth = 4
Figure 26 - Uart reception timing diagram with FIFO depth = 4
Device 1
bit0
Figure 27 - Connecting devices with flow control
UA_RX
bit1
UA_TX
CTS
RTS
bit7
parity stop
55
word1
start
Device 2
UA_RX
UA_TX
RTS
CTS
bit0
bit1
SX1441 – Bluetooth® 1.2 SoC
bit7
parity
stop
word2
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start
word2
Data Sheet