LG KF750 Service Manual page 32

3.1.8 USB
The USB block supports the implementation of a °∞High-speed" device fully compliant to USB 2.0
standard. It provides an interface between the CPU (embedded local host) and the USB wire, and
handles USB transactions with minimal CPU intervention.
The USB specification allows up to 15 pairs of endpoints. Data for each endpoint is buffered in RAM
within the USB block and is read/written from the endpoint FIFO using DMA transfers or FIFO register
access. High-speed (high throughput) endpoints can use DMA while slower endpoints can use FIFO
register access.
The USB block can request up to six DMA channels, three for IN endpoints and three for OUT
endpoints.
USB Function
USB_STP
USB_DIR
USB_CLK
USB_NXT
USB_DAT0
USB_DAT1
USB_DAT2
USB_DAT3
USB_DAT4
USB_DAT5
USB_DAT6
USB_DAT7
USB_CS_PD
VBUS
Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
Note
ULPI stop signal
ULPI direction signal
USB clock
ULPI next signal
USB data0
USB data1
USB data2
USB data3
USB data4
USB data5
USB data6
USB data7
USB chip select
Power supply for Asta USB block
Table 3-1-6. USB Signal Interface of Asta
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3. TECHNICAL BRIEF
LGE Internal Use Only