Nxp Semiconductors UM10237 用户手册
UM10237_2
© NXP B.V. 2008. All rights reserved.
User manual
Rev. 02 — 19 December 2008
463 of 792
NXP Semiconductors
UM10237
Chapter 17: LPC24XX Universal Asynchronous Receiver/Transmitter
Fig 71. 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
True
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
True
False