ZBA Inc. BT44-291S ユーザーズマニュアル
BT44-291S
Page 9 of 18
inband at 2.4GHz and ≤80dBm at 3.2GHz
8. UART Interface
BlueCore4-External Universal Asynchronous Receiver Transmitter (UART) interface
provides a simple mechanism for communicating with other serial devices using the RS232
standard
standard
(1)
.
BlueCore4-External
Figure 11.12: Universal Asynchronous Receiver
Four signals are used to implement the UART function, as shown in Figure 11.12. When
BlueCore4-External is connected to another digital device, UART_RX and UART_TX transfer
data between the two devices. The remaining two signals, UART_CTS and UART_RTS, can be
used to implement RS232 hardware flow control where both are active low indicators. All UART
connections are implemented using CMOS technology and have signalling levels of 0V and Vcc.
data between the two devices. The remaining two signals, UART_CTS and UART_RTS, can be
used to implement RS232 hardware flow control where both are active low indicators. All UART
connections are implemented using CMOS technology and have signalling levels of 0V and Vcc.
UART configuration parameters, such as Baud rate and packet format, are set using
BlueCore4-External software.
Notes:
In order to communicate with the UART at its maximum data rate using a standard PC, an
In order to communicate with the UART at its maximum data rate using a standard PC, an
accelerated serial port adapter card is required for the PC.
(1) Uses RS232 protocol but voltage levels are 0V to VDD_USB, (requires external RS232
transceiver chip)
Parameter Possible
Values
1200 Baud (≤2%Error)
Minimum
9600 Baud (≤1%Error)
Baud Rate
Maximum 3.0MBaud
(≤1%Error)
Flow Control
RTS/CTS or None
Parity
None, Odd or Even
Number of Stop Bits
1 or 2
Bits per channel
8
Table 11.7: Possible UART Settings
The UART interface is capable of resetting BlueCore4-External upon reception of a break
signal. A Break is identified by a continuous logic low (0V) on the UART_RX terminal, as shown