BC41B143A-DS-003PC Datasheet, PDF (80/94 Pages) List of Unclassifed Manufacturers – BlueCore 4-ROM Plug-n-Go Single Chip Bluetooth v2.0 + EDR System

Device Terminal Descriptions
10.10 TCXO Enable OR Function
An OR function exists for clock enable signals from a host controller and BlueCore4-ROM Plug-n-Go where either
device can turn on the clock without having to wake up the other device. PIO[3] can be used as the host clock enables
input and PIO[2] can be used as the OR output with the TCXO enable signal from BlueCore4-ROM Plug-n-Go.
VDD
TCXO
Enable
GSM System
CLK IN
CLK REQ OUT
BlueCore System
CLK REQ IN/
PIO[3]
CLK REQ OUT/
CLK IN
PIO[2]
Figure 10.30: Example TXCO Enable OR Function
On reset and up to the time the PIO has been configured, PIO[2] will be tri-state. Therefore, the developer must ensure
that the circuitry connected to this pin is pulled via a 470kΩ resistor to the appropriate power rail. This ensures that the
TCXO is oscillating at start up.
BC41B143A-ds-003Pc
Advance Information
© Cambridge Silicon Radio Limited 2005
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