• Receiver detection of break, idle, framing, FIFO overflow, and parity error conditions
• Transmitter underflow detection
• CTR/RTS hardware flow control
BT UART 4-Wire Interface - H4
The interface includes four signals: TXD, RXD, CTS and RTS. Flow control between the host and the
DR-WLS1273L-102 is byte-wise by hardware. Flow control is obtained by the following:
H O S T _ R X
H O S T T X
H o s t
P ro c e s s o r
H O S T _ C T S
H O S T _ R T S
H C I_ R X
H C I_ T X
H C I_ C T S
H C I_ R T S
D R -
S 1 2 7 3
-1 0 2
When the UART RX buffer asses the “flow control” threshold, it sets the UART_RTS signal high to stop
transmission from the host. When the UART_CTS signal is set high, the DR-WLS1273L-102 stops trans-
mitting on the interface. In case HCI_CTS is set high in the middle of transmitting a byte, the DR-
WLS1273L-102 finishes transmitting the byte and stops the transmission.
BT UART 3-Wire Interface - H5
This interface consists of three signals: TXD, RXD and GND:
HCI_RX Receive Data on the UART Interface
HCI_TX Transmit Data on the UART Interface
GND Ground
XON/XOFF software flow control is normally used.
The DR-WLS1273L-102 also supports a four-wire mode for H5, with RTS/CTS hardware flow control.
Since the same UART module is used for the 3- and 4-wire HCI UART interface, all features supported by
the 4-wire interface are also supported for the 3-wire interface. H5 features:
• Flow control configured with HCI_VS command, software XON/XOFF, hardware (RTS/CTS), or none
• Power management
• Configurable timers for re-transmission management
• CRC
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Page 6 of 31
DR-WLS1273L-102 Data Sheet - 12/13/12
RFM [ RF MONOLITHICS, INC ]
