NXP Semiconductors LPC1768 - Page 337

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User manual Rev. 3 — 19 December 2013 337 of 841
NXP Semiconductors
UM10360
Chapter 15: LPC176x/5x UART1
Fig 51. Algorithm for setting UART dividers
PCLK,
BR
Calculating UART
baudrate (BR)
DL
est
= PCLK/(16 x BR)
DL
est
is an
integer?
DIVADDVAL = 0
MULVAL = 1
Tr ue
FR
est
= 1.5
DL
est
= Int(PCLK/(16 x BR x FR
est
))
1.1 < FR
est
< 1.9?
Pick another FR
est
from
the range [1.1, 1.9]
FR
est
= PCLK/(16 x BR x DL
est
)
DIVADDVAL = table(FR
est
)
MULVAL = table(FR
est
)
DLM = DL
est
[15:8]
DLL = DL
est
[7:0]
End
False
Tr ue
False