
SC16C850
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NXP B.V. 2010. All rights reserved.
Product data sheet
Rev. 2 — 11 November 2010
37 of 55
NXP Semiconductors
SC16C850
2.5 to 3.3 V UART with 128-byte FIFOs and IrDA encoder/decoder
7.23 SC16C850 external reset condition and software reset
These two reset methods are identical and will reset the internal registers as indicated in
Table 33.
Reset state for registers
Register
Reset state
IER
IER[7:0] = 0
FCR
FCR[7:0] = 0
ISR
ISR[7:1] = 0; ISR[0] = 1
LCR
LCR[7:0] = 0
MCR
MCR[7:0] = 0
LSR
LSR[7] = 0; LSR[6:5] = 1; LSR[4:0] = 0
MSR
MSR[7:4] = input signals; MSR[3:0] = 0
EFCR
EFCR[7:0] = 0
SPR
SPR[7:0] = 1
DLL
undefined
DLM
undefined
TXLVLCNT
TXLVLCNT[7:0] = 0
RXLVLCNT
RXLVLCNT[7:0] = 0
EFR
EFR[7:0] = 0
Xon1
undefined
Xon2
undefined
Xoff1
undefined
Xoff2
undefined
TXINTLVL
TXINTLVL[7:0] = 0
RXINTLVL
RXINTLVL[7:0] = 0
FLWCNTH
FLWCNTH[7:0] = 0
FLWCNTL
FLWCNTL[7:0] = 0
CLKPRES
CLKPRES[7:0] = 0
RS485TIME
RS485TIME[7:0] = 0
AFCR2
AFCR2[7:0] = 0
AFCR1
AFCR1[7:0] = 0
Table 34.
Reset state for outputs
Output
Reset state
TX
logic 1
RTS
logic 1
DTR
logic 1
INT
logic 0
IRQ
open-drain