BC41B143A-ds-003Pc CSR, BC41B143A-ds-003Pc Datasheet - Page 80

• Manufacturer Part Number: BC41B143A-ds-003Pc
• Description: Blue Core ROM Plug-n-Go
• Manufacturer: CSR

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.
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
VDD
Enable
TCXO
Figure 10.30: Example TXCO Enable OR Function
© Cambridge Silicon Radio Limited 2005
Advance Information
CLK IN
CLK REQ IN/
PIO[3]
CLK IN
BlueCore System
GSM System
CLK REQ OUT/
CLK REQ OUT
PIO[2]
Device Terminal Descriptions
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