BC41B143A-DS-003PC Datasheet, PDF (57/94 Pages) List of Unclassifed Manufacturers – BlueCore 4-ROM Plug-n-Go Single Chip Bluetooth v2.0 + EDR System

Device Terminal Descriptions
The UART interface is capable of resetting BlueCore4-ROM Plug-n-Go 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 10.11. 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, BlueCore4-ROM Plug-n-Go can emit a break
character that may be used to wake the host.
Figure 10.11: 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 10.5 shows a list of commonly used baud rates and their associated values for the PS 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 PS Key according to the formula in Equation 10.7.
Baud Rate
1200
2400
4800
9600
19200
38400
57600
76800
115200
230400
460800
921600
1382400
1843200
2764800
Baud Rate = ^{PSKEY_ UART_ BAUD_ RATE}
0.004096
Equation 10.7: Baud Rate
Persistent Store Value
Hex
Dec
0x0005
5
0x000a
10
0x0014
20
0x0027
39
0x004f
79
0x009d
157
0x00ec
236
0x013b
315
0x01d8
472
0x03b0
944
0x075f
1887
0x0ebf
3775
0x161e
5662
0x1d7e
7550
0x2c3d
11325
Table 10.5: 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%
0.00%
0.00%
BC41B143A-ds-003Pc
Advance Information
© Cambridge Silicon Radio Limited 2005
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