sc16c754bibm NXP Semiconductors, sc16c754bibm Datasheet - Page 30

• Manufacturer Part Number: sc16c754bibm
• Description: 5 V, 3.3 V And 2.5 V Quad Uart, 5 Mbit/s Max. With 64-byte Fifos
• Manufacturer: NXP Semiconductors

Philips Semiconductors
9397 750 14668
Product data sheet
7.9 Interrupt Identification Register (IIR)
The IIR is a read-only 8-bit register which provides the source of the interrupt in a
prioritized manner.
Table 17:
The interrupt priority list is shown in
Table 18:
Bit
7-6
5
4
3-1
0
Priority
level
1
2
2
3
4
5
6
Symbol
IIR[7:6]
IIR[5]
IIR[4]
IIR[3:1]
IIR[0]
IIR[5]
0
0
0
0
0
0
1
Interrupt Identification Register bits description
Interrupt priority list
IIR[4]
0
0
0
0
0
1
0
Description
Mirror the contents of FCR[0].
RTS/CTS LOW-to-HIGH change of state.
1 = Xoff/Special character has been detected.
3-bit encoded interrupt. See
Interrupt status.
5 V, 3.3 V and 2.5 V quad UART, 5 Mbit/s (max.) with 64-byte FIFOs
Table 17
logic 0 = an interrupt is pending
logic 1 = no interrupt is pending
Rev. 02 — 13 June 2005
IIR[3]
0
1
0
0
0
0
0
shows Interrupt Identification Register bit settings.
IIR[2]
1
1
1
0
0
0
0
Table
18.
IIR[1]
1
0
0
1
0
0
0
Table
18.
IIR[0]
0
0
0
0
0
0
0
© Koninklijke Philips Electronics N.V. 2005. All rights reserved.
Source of the interrupt
Receiver Line Status error
Receiver time-out interrupt
RHR interrupt
THR interrupt
Modem interrupt
Received Xoff signal/
special character
CTS, RTS change of state from
active (LOW) to inactive (HIGH)
SC16C754B
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