BC41B143A-DS-001PE Datasheet, PDF (64/102 Pages) List of Unclassifed Manufacturers – BlueCpre 4-ROM Single Chip Bluetooth v2.0 System with EDR

Device Terminal Descriptions
The UART interface is capable of resetting BlueCore4-ROM 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 10.12. 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 can emit a Break
character that may be used to wake the Host.
t
BRK
UART RX
Figure 10.12: 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 10.4 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 10.9.
Baud Rate = ^{PSKEY_UART_BAUD_RATE}
0.004096
Equation 10.9: Baud Rate
Baud Rate
1200
2400
4800
9600
19200
38400
57600
76800
115200
230400
460800
921600
1382400
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
Table 10.6: Standard Baud Rates ⁽¹⁾
Note:
(1) _{Table will be extended to cover EDR}
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%
BC41B143A-ds-001Pe
This material is subject to CSR’s non-disclosure agreement
Production Information
© Cambridge Silicon Radio Limited 2005
Page 64 of 102