User's Manual

NEMO Bluetooth Radio Module
Solutions for a Real Time World Datasheet
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Copyright Unigen Corporation, 2008
B
OOTING NEMO ROM
The NEMO module contains the CSR BlueCore 6 ROM device. The firmware is loaded from
BlueCore’s internal ROM. The NEMO module is boot-strapped to use the UART interface upon
power up. The BCSP communication protocol along with the BCCMD protocol is used over the
UART. PIO 4 must be held low in order to boot into BCSP over the UART successfully.
Configuration of NEMO is handled through the UART interface and BCCMD protocol. The
Bluetooth address, UART baud rate, PCM configuration and country code are all parameters that
can be configured on the ROM device upon power up. These parameters are programmed into
Persistent Store Keys in RAM and are loaded into firmware after a soft reset.
NEMO Boot Process
1. Power up NEMO with PIO4 pulled low.
2. Initialize BCSP communications over the UART link.
3. Load and program the PSKEYS via BCCMD commands necessary for the initialization
4. Issue BCCMD warm_reset command
5. Re-initialize BCSP communications
6. Module is ready for operation
This process needs to be performed during every cold boot or hard reset on NEMO.
UART Auto Baud Rate
The NEMO module can support booting into UART mode without pre-configuration of the baud
rate, and clock reference. Although a 26MHz internal crystal oscillator is built into the module, the
CSR BlueCore device needs to be configured to use the clock reference for radio and UART
communication purposes. The CSR device support an “AUTOBAUD” adaption algorithm where the
Host can communicate over the UART link to load configuration PSKEYS into RAM and perform
initialization of the module.
The AUTOBAUD UART baud rate adaption mechanism starts by treating the UARTS RXD data line
as a simple PIO input, and it records the hosts initial UART traffic in a buffer. The mechanism
then examines the recorded data stream to determine the times between signal level transitions
and, from this, derives the baud rate the host is using. The mechanism then matches the
measured baud rate.