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UM10375
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© NXP B.V. 2011. All rights reserved.
User manual
Rev. 3 — 14 June 2011
138 of 368
NXP Semiconductors
UM10375
Chapter 10: LPC13xx USB device controller
10.6 General description
The architecture of the USB device controller is shown below in
.
10.6.1 Analog transceiver
The USB Device Controller has a built-in analog transceiver (ATX). The USB ATX
sends/receives the bi-directional USB_DP and USB_DM signals of the USB bus.
10.6.2 Serial Interface Engine (SIE)
The SIE implements the full USB protocol layer. It is completely hardwired for speed and
needs no firmware intervention. It handles transfer of data between the endpoint buffers in
EP_RAM and the USB bus. The functions of this block include: synchronization pattern
recognition, parallel/serial conversion, bit stuffing/de-stuffing, CRC checking/generation,
PID verification/generation, address recognition, and handshake evaluation/generation.
10.6.3 Endpoint RAM (EP_RAM)
Each endpoint buffer is implemented as an SRAM based FIFO. The SRAM dedicated for
this purpose is called the EP_RAM. Each endpoint has a reserved space in the EP_RAM.
The total EP_RAM space is fixed. All endpoints are realized automatically.
10.6.4 EP_RAM access control
The EP_RAM Access Control logic handles transfer of data from/to the EP_RAM and the
sources that can access it: the CPU (via the Register Interface) and the SIE.
Fig 16. USB device controller block diagram
register
interface
(APB slave)
EP_RAM
ACCESS
CONTROL
REGISTER
INTERFACE
SERIAL
INTERFACE
ENGINE
USB DEVICE
BLOCK
U
SB AT
X
BUS
MASTER
INTERFACE
AP
B BU
S
V
BUS
USB_CONNECT
USB_DP
USB_DM