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UM10375
All information provided in this document is subject to legal disclaimers.
© NXP B.V. 2011. All rights reserved.
User manual
Rev. 3 — 14 June 2011
136 of 368
10.1 How to read this chapter
The USB device controller is available on parts LPC1342 and LPC1343 only.
10.2 Basic configuration
The USB device is configured using the following registers:
1. Pins: The USB pins must be configured in the IOCONFIG register block (
).
2. Power: In the SYSAHBCLKCTRL register, set bit 14 (
) for the USB register
interface. The USB PHY must be powered through the PDRUNCFG register
(
)
3. Clock: Enable the USB clock by writing to the USBCLKDIV register (
). The
USB clock can be selected from the dedicated USB PLL or the main clock (
).
For details see
.
10.3 Introduction
The Universal Serial Bus (USB) is a four-wire bus that supports communication between a
host and one or more (up to 127) peripherals. The host controller allocates the USB
bandwidth to attached devices through a token-based protocol. The bus supports hot
plugging and dynamic configuration of the devices. All transactions are initiated by the
host controller.
The host schedules transactions in 1 ms frames. Each frame contains a Start-Of-Frame
(SOF) marker and transactions that transfer data to or from device endpoints. Each device
can have a maximum of 5 logical or 10 physical endpoints. There are four types of
transfers defined for the endpoints. Control transfers are used to configure the device.
Interrupt transfers are used for periodic data transfer. Bulk transfers are used when the
rate of transfer is not critical. Isochronous transfers have guaranteed delivery time but no
error correction.
For more information on the Universal Serial Bus, see the USB Implementers Forum
website.
The USB device controller on the LPC134x enables full-speed (12 Mb/s) data exchange
with a USB host controller.
UM10375
Chapter 10: LPC13xx USB device controller
Rev. 3 — 14 June 2011
User manual
Table 158. USB related acronyms, abbreviations, and definitions used in this chapter
Acronym/abbreviation Description
AHB
Advanced High-performance bus
ATLE
Auto Transfer Length Extraction
ATX
Analog Transceiver
EOP
End-Of-Packet
EP
Endpoint
EP_RAM
Endpoint RAM