
SC16C850
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NXP B.V. 2010. All rights reserved.
Product data sheet
Rev. 2 — 11 November 2010
27 of 55
NXP Semiconductors
SC16C850
2.5 to 3.3 V UART with 128-byte FIFOs and IrDA encoder/decoder
7.5 Line Control Register (LCR)
The Line Control Register is used to specify the asynchronous data communication
format. The word length, the number of stop bits, and the parity are selected by writing the
appropriate bits in this register.
0
ISR[0]
INT status.
logic 0 = an interrupt is pending and the ISR contents may be used as a
pointer to the appropriate interrupt service routine
logic 1 = no interrupt pending (normal default condition)
Table 14.
Interrupt Status Register bits description …continued
Bit
Symbol
Description
Table 15.
Line Control Register bits description
Bit
Symbol
Description
7
LCR[7]
Divisor latch enable. The internal baud rate counter latch and Enhanced
Feature mode enable.
logic 0 = divisor latch disabled (normal default condition)
logic 1 = divisor latch enabled
6
LCR[6]
Set break. 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 for alerting the
remote receiver to a line break condition
5:3
LCR[5:3]
Programs the parity conditions (see
Table 16).
2
LCR[2]
Stop bits. The length of stop bit is specified by this bit in conjunction with the
logic 0 or cleared = default condition
1:0
LCR[1:0]
Word length bits 1, 0. These two bits specify the word length to be
logic 0 or cleared = default condition
Table 16.
LCR[5:3] parity selection
LCR[5]
LCR[4]
LCR[3]
Parity selection
XX
0
no parity
0
01odd parity
0
11even parity
1
0
1
forced parity ‘1’
1
forced parity ‘0’
Table 17.
LCR[2] stop bit length
LCR[2]
Word length (bits)
Stop bit length (bit times)
0
5, 6, 7, 8
1
15
11
2
16, 7, 8
2