SC16C754B NXP Semiconductors, SC16C754B Datasheet - Page 16

• Manufacturer Part Number: SC16C754B
• Description: 5 V - 3.3 V and 2.5 V quad UART - 5 Mbit/s (max.)
• Manufacturer: NXP Semiconductors

NXP Semiconductors
SC16C754B_4
Product data sheet
6.5.1 Interrupt mode operation
6.5.2 Polled mode operation
In interrupt mode (if any bit of IER[3:0] is ‘1’) the processor is informed of the status of the
receiver and transmitter by an interrupt signal, INT. Therefore, it is not necessary to
continuously poll the Line Status Register (LSR) to see if any interrupt needs to be
serviced.
In polled mode (IER[3:0] = 0000) the status of the receiver and transmitter can be
checked by polling the Line Status Register (LSR). This mode is an alternative to the FIFO
interrupt mode of operation where the status of the receiver and transmitter is
automatically known by means of interrupts sent to the CPU.
mode operation.
Fig 9.
Fig 10. FIFO polled mode operation
Interrupt mode operation
Figure 9
PROCESSOR
PROCESSOR
shows interrupt mode operation.
5 V, 3.3 V and 2.5 V quad UART, 5 Mbit/s (max.) with 64-byte FIFOs
Rev. 04 — 6 October 2008
IOW / IOR
IOW / IOR
INT
THR
THR
Figure 10
IIR
LSR
IER
IER
1
0
SC16C754B
1
0
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RHR
RHR
002aaa230
002aaa231
1
0
shows FIFO polled
1
0
© NXP B.V. 2008. All rights reserved.
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