UM10237_2 © NXP B.V. 2008. All rights reserved.
User manual Rev. 02 — 19 December 2008 395 o f 792
NXP Semiconductors UM10237
Chapter 15: LPC24XX USB OTG controller

The following figures show different ways to realize connections to an USB device using

ports U1 and U2. The example described here uses an ISP1301 (NXP) for the external

OTG transceiver and the USB Host power switch LM3526-L (National Semiconductors).

6.1 Connecting port U1 to an external OTG transceiver

For OTG functionality an external OTG transceiver must be connected to the LPC2400

device. There are two ways to connect the OTG transceiver (here ISP1301) to port U1:

Table 361. USB OTG port 1 pins
Pin name Direction Description Pin category
VBUS IV
BUS status input. When this function is not enabled
via its corresponding PINSEL register, it is driven
HIGH internally.
USB Connector
Port U1
USB_D+1 I/O Positive differential data USB Connector
USB_D1 I/O Negative differential data USB Connector
USB_CONNECT1 O SoftConnect control signal Control
USB_UP_LED1 O GoodLink LED control signal Control
USB_INT1I OTG ATX interrupt External OTG transceiver
USB_SCL1 I/O I2C serial clock External OTG transceiver
USB_SDA1 I/O I2C serial data External OTG transceiver
USB_TX_E1O Transmit enable External OTG transceiver
USB_TX_DP1 O D+ transmit data External OTG transceiver
USB_TX_DM1 O D transmit data External OTG transceiver
USB_RCV1 I Differential receive data External OTG transceiver
USB_RX_DP1 I D+ receive data External OTG transceiver
USB_RX_DM1 I D receive data External OTG transceiver
USB_LS1 O Low speed status (applies to host functionality only) External OTG transceiver
USB_SSPND1 O Bus suspend status External OTG transceiver
USB_PPWR1O Port power enable Host power switch
USB_PWRD1 I Port power status Host power switch
USB_OVRCR1 I Over-current status Host power switch
USB_HSTEN1 O Host enabled status
Port U2
USB_D+2 I/O Positive differential data USB Connector
USB_D2 I/O Negative differential data USB Connector
USB_CONNECT2 O SoftConnect control signal Control
USB_UP_LED2 O GoodLink LED control signal Control
USB_PPWR2O Port power enable Host power switch
USB_PWRD2 I Port power status Host power switch
USB_OVRCR2 I Over-current status Host power switch
USB_HSTEN2 O Host enabled status Control