UM10503
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User manual
Rev. 1.3 — 6 July 2012
619 of 1269
NXP Semiconductors
UM10503
Chapter 24: LPC43xx USB1 Host/Device controller
24.6.16 USB Mode register (USBMODE)
The USBMODE register sets the USB mode for the USB controller. The possible modes
are Device, Host, and Idle mode.
24.6.16.1 Device mode
Table 483. Port states as described by the PE and SUSP bits in the PORTSC1 register
PE bit
SUSP bit
Port state
0
0 or 1
disabled
1
0
enabled
1
1
suspend
Table 484. USB Mode register in device mode (USBMODE_D - address 0x4000 71A8) bit description
Bit
Symbol Value
Description
Reset
value
Access
1:0
CM1_0
Controller mode
The controller defaults to an idle state and needs to be initialized to the
desired operating mode after reset. This register can only be written once
after reset. If it is necessary to switch modes, software must reset the
controller by writing to the RESET bit in the USBCMD register before
reprogramming this register.
00
R/ WO
0x0
Idle
0x1
Reserved
0x2
Device controller
0x3
Host controller
2
ES
Endian select
This bit can change the byte ordering of the transfer buffers to match the
host microprocessor bus architecture. The bit fields in the microprocessor
interface and the DMA data structures (including the setup buffer within the
device QH) are unaffected by the value of this bit, because they are based
upon 32-bit words.
0
R/W
0
Little endian: first byte referenced in least significant byte of 32-bit word.
1
Big endian: first byte referenced in most significant byte of 32-bit word.
3
SLOM
Setup Lockout mode
In device mode, this bit controls behavior of the setup lock mechanism. See
.
0
R/W
0
Setup Lockouts on
1
Setup Lockouts Off (DCD requires the use of Setup Buffer Tripwire in
USBCMD)