14 bits divisor:
1/(DLH,DLL)
DLH
DLL
16x divisor (SIR)
41x,42x (MIR)
MDR1[2:0]:
MODE_SELECT
SIR
MIR
TXIR SIR/MIR
RXIR SIR/MIR
6x divisor
FIR
TXIR FIR
RXIR FIR
77x divisor (1.6
m
s on)
341x divisor (7.1
m
s off)
1.6/7.1
m
s SIP (MIR or FIR)
or
1.6
m
s pulse (SIR)
uart-033
Public Version
www.ti.com
UART/IrDA/CIR Functional Description
Figure 19-32. Baud Rate Generator
CAUTION
Before trying to initialize or modify clock parameter controls (UARTi.
it
is
mandatory
to
set
MODE_SELECT=DISABLE
Failure to observe this rule can result in unpredictable module behavior.
19.4.4.2.2 Choosing the Appropriate Divisor Value
•
SIR mode: Divisor value = Operating frequency/(16x baud rate)
•
MIR mode: Divisor value = Operating frequency/(41x/42x baud rate)
•
FIR mode: Divisor value = None
lists the IrDA baud rate settings.
Table 19-34. IrDA Baud Rates Settings
Baud Rate
IR Mode
Baud Multiple
Encoding
DLH, DLL
Actual Baud
Error (%)$
Source Jitter
Pulse duration
(Decimal)
Rate
(%)
2.4 Kbps
SIR
16x
3/16
1250
2.4 Kbps
0
0
78.1 εs
9.6 Kbps
SIR
16x
3/16
312
9.6153 Kbps
+0.16
0
19.5 µs
19.2 Kbps
SIR
16x
3/16
156
19.231 Kbps
+0.16
0
9.75 µs
38.4 Kbps
SIR
16x
3/16
78
38.462 Kbps
+0.16
0
4.87 µs
57.6 Kbps
SIR
16x
3/16
52
57.692 Kbps
+0.16
0
3.25 µs
115.2 Kbps
SIR
16x
3/16
26
115.38 Kbps
+0.16
0
1.62 µs
2911
SWPU177N – December 2009 – Revised November 2010
UART/IrDA/CIR
Copyright © 2009–2010, Texas Instruments Incorporated