2 software interface, Nxp semiconductors – NXP Semiconductors LPC24XX UM10237 User Manual
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© NXP B.V. 2009. All rights reserved.
User manual
Rev. 04 — 26 August 2009
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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
.
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_INT1
I
OTG ATX interrupt
External OTG transceiver
USB_SCL1
I/O
I
2
C serial clock
External OTG transceiver
USB_SDA1
I/O
I
2
C serial data
External OTG transceiver
USB_TX_E1
O
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_PPWR1
O
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_D
−2
I/O
Negative differential data
USB Connector
USB_CONNECT2 O
SoftConnect control signal
Control
USB_UP_LED2
O
GoodLink LED control signal
Control
USB_PPWR2
O
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