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UM10237_2
© NXP B.V. 2008. All rights reserved.
User manual
Rev. 02 — 19 December 2008
338 of 792
NXP Semiconductors
UM10237
Chapter 13: LPC24XX USB device controller
9.3 Device interrupt registers
9.3.1 USB Interrupt Status register (USBIntSt - 0xE01F C1C0)
The USB Device Controller has three interrupt lines. This register allows software to
determine their status with a single read operation. All three interrupt lines are ORed
together to a single channel of the vectored interrupt controller. This register also contains
the USB_NEED_CLK status and EN_USB_INTS control bits. USBIntSt is a read/write
register.
Table 296. USB Clock Status register (USBClkSt - 0xFFE0 CFF8) bit description
Bit
Symbol
Description
Reset
value
0
-
Reserved, user software should not write ones to
reserved bits. The value read from a reserved bit is
not defined.
NA
1
DEV_CLK_ON
Device clock on. The usbclk input to the device
controller is active.
0
2
-
Reserved, user software should not write ones to
reserved bits. The value read from a reserved bit is
not defined.
NA
3
PORTSEL_CLK_ON
Port select register clock on.
NA
4
AHB_CLK_ON
AHB clock on.
0
31:5
-
Reserved, user software should not write ones to
reserved bits. The value read from a reserved bit is
not defined.
NA
Table 297. USB Interrupt Status register (USBIntSt - address 0xE01F C1C0) bit description
Bit
Symbol
Description
Reset
value
0
USB_INT_REQ_LP
Low priority interrupt line status. This bit is read only.
0
1
USB_INT_REQ_HP
High priority interrupt line status. This bit is read only.
0
2
USB_INT_REQ_DMA
DMA interrupt line status. This bit is read only.
0
7:3
-
Reserved, user software should not write ones to reserved bits. The
value read from a reserved bit is not defined.
NA