CSR BlueCore CSR8640 BGA, User Manual

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When CSR8640 BGA is connected to another digital device, UART_RX and UART_TX transfer data between the 2
devices. The remaining 2 signals, UART_CTS and UART_RTS, implement optional RS232 hardware flow control
where both are active low indicators.
UART configuration parameters, such as baud rate and packet format, are set using CSR8640 BGA firmware.
Note:
To communicate with the UART at its maximum data rate using a standard PC, the PC requires an accelerated
serial port adapter card.
Table 7.1 shows the possible UART settings.
Parameter Possible Values
Baud rate
Minimum
1200 baud (≤2%Error)
9600 baud (≤1%Error)
Maximum 4Mbaud (≤1%Error)
Flow control RTS/CTS or None
Parity None, Odd or Even
Number of stop bits 1 or 2
Bits per byte 8
Table 7.1: Possible UART Settings
Note:
Load the DFU boot loader into the internal ROM before using the UART or USB interface. Use the SPI for this
initial flash programming.
Table 7.2 lists common baud rates and their associated values for the PSKEY_UART_BAUDRATE. There is no
requirement to use these standard values. Any baud rate within the supported range is set in the PS Key according
to the formula in Equation 7.1.
Baud Rate = PSKEY_UART_BAUDRATE
0.004096
Equation 7.1: Baud Rate
Baud Rate
Persistent Store Value
Error
Hex Dec
1200 0x0005 5 1.73%
2400 0x000a 10 1.73%
4800 0x0014 20 1.73%
9600 0x0027 39 -0.82%
Advance Information
This material is subject to CSR's non-disclosure agreement
© Cambridge Silicon Radio Limited 2011
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CSR8640 BGA
Data Sheet