BC352239A Datasheet, PDF (64/116 Pages) List of Unclassifed Manufacturers – BlueCore 3-Multimedia External

Device Terminal Descriptions
The UART interface is capable of resetting BlueCore3-Multimedia External upon reception of a break signal. A
Break is identified by a continuous logic low (0V) on the UART_RX terminal, as shown in Figure 8.. If t_BRK is
longer than the value, defined by the PS Key PSKEY_HOST_IO_UART_RESET_TIMEOUT, (0x1a4), a reset will
occur. This feature allows a host to initialise the system to a known state. Also, BlueCore3-Multimedia External
can emit a Break character that may be used to wake the Host.
UART RX
t
BRK
Figure 8.21: Break Signal
Note:
The DFU boot loader must be loaded into the Flash device before the UART or USB interfaces can be used.
This initial flash programming can be done via the SPI.
Table 8. shows a list of commonly used Baud rates and their associated values for the Persistent Store Key
PSKEY_UART_BAUD_RATE (0x204). There is no requirement to use these standard values. Any Baud rate
within the supported range can be set in the Persistent Store Key according to the formula in Equation 8.9.
Baud Rate = ^{PSKEY_UART_BAUD_RATE}
0.004096
Equation 8.9: Baud Rate
Baud Rate
1200
2400
4800
9600
19200
38400
57600
76800
115200
230400
460800
921600
1382400
Persistent Store Value
Hex
Dec
0x0005
0x000a
0x0014
0x0027
0x004f
0x009d
0x00ec
0x013b
0x01d8
0x03b0
0x075f
0x0ebf
0x161e
5
10
20
39
79
157
236
315
472
944
1887
3775
5662
Table 8.17: Standard Baud Rates
Error
1.73%
1.73%
1.73%
-0.82%
0.45%
-0.18%
0.03%
0.14%
0.03%
0.03%
-0.02%
0.00%
-0.01%
BC352239A-ds-001Pc
© Cambridge Silicon Radio Limited 2004
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