UM10237_2 © NXP B.V. 2008. All rights reserved.
User manual Rev. 02 — 19 December 2008 390 o f 792
NXP Semiconductors UM10237
Chapter 14: LPC24XX USB Host controller

3.1.1 USB host usage note

Both ports can be configured as USB hosts. For details on how to connect the USB ports,
see the USB OTG chapter, Section 15–6 “Pin configuration.
The USB device/host/OTG controller is disabled after RESET and must be enabled by
writing a 1 to the PCUSB bit in the PCONP register, see Table4–63.
3.2 Software interface
The software interface of the USB host block consists of a register view and the format
definitions for the endpoint descriptors. For details on these two aspects see the OHCI
specification. The register map is shown in the next subsection.

3.2.1 Register map

The following registers are located in the AHB clock ‘cclk’ domain. They can be accessed
directly by the processor. All registers are 32 bit wide and aligned in the word address
boundaries.
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
U2PWRD2 I Port power status Host power switch
USB_OVRCR2 I Over-current status Host power switch
USB_HSTEN2 O Host enabled status Control
Table 359. USB OTG port pins
Pin name Direction Description Pin category