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Section 22 USB Function Module (USB)
22.9
Example of USB External Circuitry
1. USB Transceiver
This module supports the built-in transceiver only, not the external transceiver.
2. D+ Pull-Up Control
The PUPDPLS pin is used for D+ pull-up control. PUPDPLS is driven high by the
PULLUP_E bit of the DMA register when the USB cable VBUS is connected.
Thus, USB host/hub connection notification (D+ pill-up) is enabled.
3. Detection of USB Cable Connection/Disconnection
As USB states, etc., are managed by hardware in this module, a VBUS signal that recognizes
connection/disconnection is necessary. The power supply signal (VBUS) in the USB cable is
used for this purpose. However, if the cable is connected to the USB host/hub when the
function (system installing this LSI) power is off, a voltage (5 V) will be applied from the USB
host/hub. Therefore, an IC (such as an HD74LV1G08A or 2G08A) that allows voltage
application when the system power is off should be connected externally.
Rev. 1.00 Mar. 12, 2008 Page 890 of 1178
REJ09B0403-0100
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