BC41B143A-DS-001PE Datasheet, PDF (69/102 Pages) List of Unclassifed Manufacturers – BlueCpre 4-ROM Single Chip Bluetooth v2.0 System with EDR

Device Terminal Descriptions
10.5.6 Suspend Current
All USB devices must permit the USB controller to place them in a USB Suspend mode. While in USB Suspend,
bus powered devices must not draw more than 0.5mA from USB VBUS (self powered devices may draw more
than 0.5mA from their own supply). This current draw requirement prevents operation of the radio by bus
powered devices during USB Suspend.
The voltage regulator circuit itself should draw only a small quiescent current (typically less than 100μA) to
ensure adherence to the suspend current requirement of the USB specification. This is not normally a problem
with modern regulators. Ensure that external LEDs and/or amplifiers can be turned off by BlueCore4-ROM. The
entire circuit must be able to enter the suspend mode. (For more details on USB Suspend, see separate CSR
documentation).
10.5.7 Detach and Wake-Up Signalling
BlueCore4-ROM can provide out-of-band signalling to a host controller by using the control lines called
‘USB_DETACH’ and ‘USB_WAKE_UP’. These are outside the USB specification (no wires exist for them inside
the USB cable), but can be useful when embedding BlueCore4-ROM into a circuit where no external USB is
visible to the user. Both control lines are shared with PIO pins and can be assigned to any PIO pin by setting the
PS Keys PSKEY_USB_PIO_DETACH and PSKEY_USB_PIO_WAKEUP to the selected PIO number.
USB_DETACH is an input which, when asserted high, causes BlueCore4-ROM to put USB_DN and USB_DP in
a high impedance state and turned off the pull-up resistor on D+. This detaches the device from the bus and is
logically equivalent to unplugging the device. When USB_DETACH is taken low, BlueCore4-ROM will connect
back to USB and await enumeration by the USB host.
USB_WAKE_UP is an active high output (used only when USB_DETACH is active) to wake up the host and
allow USB communication to recommence. It replaces the function of the software USB WAKE_UP message
(which runs over the USB cable), and cannot be sent while BlueCore4-ROM is effectively disconnected from the
bus.
10ms max
10ms max
USB_DETACH
10ms max
No max
USB_WAKE_UP
Port_Impedance
USB_DP
USB_DN
USB_PULL_UP
Disconnected
Figure 10.16: USB_DETACH and USB_WAKE_UP Signal
10.5.8 USB Driver
A USB Bluetooth device driver is required to provide a software interface between BlueCore4-ROM and
Bluetooth software running on the host computer. Suitable drivers are available from www.csrsupport.com.
BC41B143A-ds-001Pe
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