BCM20706 Data Sheet
PCM Interface
Table 2 contains example values to generate common baud rates with a 48 MHz UART clock.
Table 2: Common Baud Rate Examples, 48 MHz Clock
Baud Rate (bps)
High Rate
Low Rate
Mode
Error (%)
6M
0xFF
0xFF
0x0
0xF8
0xF4
0xFF
0xFF
0xFE
0xFD
0xFD
0xF3
0xE6
0xCC
0xB2
High rate
High rate
Normal
Normal
Normal
Normal
Normal
Normal
Normal
Normal
Normal
0
4M
0
3M
0
2M
0x44
0x0
0
1.5M
1M
0
0x0
0
921600
230400
115200
57600
38400
0x22
0x0
0.16
0.16
–0.08
0.04
0
0x1
0x1
0x11
Normally, the UART baud rate is set by a configuration record downloaded after reset. Support for changing the
baud rate during normal HCI UART operation is included through a vendor-specific command that allows the
host to adjust the contents of the baud rate registers.
The BCM20706 UART operates correctly with the host UART as long as the combined baud rate error of the
two devices is within ±2%.
Peripheral UART Interface
The BCM20706 has a second UART that may be used to interface to other peripherals. This peripheral UART
is accessed through the optional I/O ports, which can be configured individually and separately for each
functional pin as shown in Table 3.
Table 3: BCM20706 Peripheral UART
Pin Name
Configured pin name P0
P31
pUART_TX
pUART_RX
pUART_CTS_N
pUART_RTS_N
P2
P3
–
P6
P33
P30
PCM Interface
2
The BCM20706 includes a PCM interface that shares pins with the I S interface. The PCM Interface on the
BCM20706 can connect to linear PCM codec devices in master or slave mode. In master mode, the BCM20706
generates the PCM_CLK and PCM_SYNC signals. In slave mode, these signals are provided by another master
on the PCM interface and are inputs to the BCM20706.
Broadcom®
Bluetooth SoC
May 19, 2016 • 20706-DS202-R
Page 17
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