SC16IS752 Datasheet, PDF (24/59 Pages) NXP Semiconductors – Dual UART with I2C-bus/SPI interface, 64 bytes of transmit and receive FIFOs, IrDA SIR built-in support

NXP Semiconductors
SC16IS752/SC16IS762
Dual UART with I²C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
8.5 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 13 shows Interrupt Identification Register bit settings.
Table 13. Interrupt Identification Register bits description
Bit
Symbol Description
7:6
IIR[7:6]
Mirror the contents of FCR[0].
5:1
IIR[5:1]
5-bit encoded interrupt. See Table 14.
0
IIR[0]
Interrupt status.
logic 0 = an interrupt is pending
logic 1 = no interrupt is pending
Table 14. Interrupt source
Priority IIR[5] IIR[4] IIR[3]
level
1
0
0
0
2
0
0
1
2
0
0
0
3
0
0
0
4
0
0
0
5
1
1
0
6
0
1
0
7
1
0
0
IIR[2]
1
1
1
0
0
0
0
0
IIR[1]
1
0
0
1
0
0
0
0
IIR[0]
0
0
0
0
0
0
0
0
Source of the interrupt
Receive Line Status error
Receiver time-out interrupt
RHR interrupt
THR interrupt
modem interrupt^[1]
input pin change of state^[1]
received Xoff signal/special
character
CTS, RTS change of state
from active (LOW) to
inactive (HIGH)
[1] Modem interrupt status must be read via MSR register and GPIO interrupt status must be read via IOState
register.
8.6 Line Control Register (LCR)
This register controls the data communication format. The word length, number of stop
bits, and parity type are selected by writing the appropriate bits to the LCR. Table 15
shows the Line Control Register bit settings.
Table 15. Line Control Register bits description
Bit
Symbol Description
7
LCR[7]
Divisor latch enable.
logic 0 = divisor latch disabled (normal default condition)
logic 1 = divisor latch enabled
6
LCR[6]
Break control bit. When enabled, the Break control bit causes a break
condition to be transmitted (the TX output is forced to a logic 0 state).
This condition exists until disabled by setting LCR[6] to a logic 0.
logic 0 = no TX break condition (normal default condition)
logic 1 = forces the transmitter output (TX) to a logic 0 to alert the
communication terminal to a line break condition
SC16IS752_SC16IS762_6
Product data sheet
Rev. 06 — 19 December 2006
© NXP B.V. 2006. All rights reserved.
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