Datasheet

UM10398 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2014. All rights reserved.
User manual Rev. 12.3 — 10 June 2014 202 of 547
NXP Semiconductors
UM10398
Chapter 13: LPC111x/LPC11Cxx UART
13.5.5 UART Interrupt Identification Register (U0IIR - 0x4004 8008, Read
Only)
U0IIR provides a status code that denotes the priority and source of a pending interrupt.
The interrupts are frozen during a U0IIR access. If an interrupt occurs during a U0IIR
access, the interrupt is recorded for the next U0IIR access.
Bits U0IIR[9:8] are set by the auto-baud function and signal a time-out or end of auto-baud
condition. The auto-baud interrupt conditions are cleared by setting the corresponding
Clear bits in the Auto-baud Control Register.
9 ABTOINTEN Enables the auto-baud time-out interrupt. 0
0 Disable auto-baud time-out Interrupt.
1 Enable auto-baud time-out Interrupt.
31:10 - Reserved, user software should not write ones to reserved
bits. The value read from a reserved bit is not defined.
NA
Table 189. UART Interrupt Enable Register (U0IER - address 0x4000 8004 when DLAB = 0) bit
description
…continued
Bit Symbol Value Description Reset
value
Table 190. UART Interrupt Identification Register (U0IIR - address 0x4004 8008, Read Only)
bit description
Bit Symbol Valu
e
Description Reset
value
0 INTSTATUS Interrupt status. Note that U0IIR[0] is active low. The
pending interrupt can be determined by evaluating
U0IIR[3:1].
1
0 At least one interrupt is pending.
1 No interrupt is pending.
3:1 INTID Interrupt identification. U0IER[3:1] identifies an interrupt
corresponding to the UART Rx FIFO. All other combinations
of U0IER[3:1] not listed below are reserved (100,101,111).
0
0x3 1 - Receive Line Status (RLS).
0x2 2a - Receive Data Available (RDA).
0x6 2b - Character Time-out Indicator (CTI).
0x1 3 - THRE Interrupt.
0x0 4 - Modem interrupt.
5:4 - Reserved, user software should not write ones to reserved
bits. The value read from a reserved bit is not defined.
NA
7:6 FIFOENABLE These bits are equivalent to U0FCR[0]. 0
8 ABEOINT End of auto-baud interrupt. True if auto-baud has finished
successfully and interrupt is enabled.
0
9 ABTOINT Auto-baud time-out interrupt. True if auto-baud has timed
out and interrupt is enabled.
0
31:10 - Reserved, user software should not write ones to reserved
bits. The value read from a reserved bit is not defined.
NA