DRAFT
DRAFT DRAFT DR
DRAFT DRAFT DRAFT
D
RAF
DRAFT DRAFT DRA
FT D
RAFT DR
AFT D
DRA
FT DRAFT DRAFT
D
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DRAFT
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UM10601
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© NXP B.V. 2012. All rights reserved.
Preliminary user manual
Rev. 1.0 — 7 November 2012
29 of 313
NXP Semiconductors
UM10601
Chapter 4: LPC800 System configuration (SYSCON)
4.6.19 USART fractional generator multiplier value register
All USART peripherals share a common clock U_PCLK, which can be adjusted by a
fractional divider:
U_PCLK = UARTCLKDIV/(1 + MULT/DIV).
UARTCLKDIV is the USART clock configured in the UARTCLKDIV register.
The fractional portion (1 + MULT/DIV) is determined by the two USART fractional divider
registers in the SYSCON block:
1. The DIV denominator of the fractional divider value is programmed in the
.
2. The MULT value programmed in this register is the numerator of the fractional divider
value used by the fractional rate generator to create the fractional component to the
baud rate.
See also:
Section 15.3.1 “Configure the USART clock and baud rate”
Section 15.7.1 “Clocking and Baud rates”
4.6.20 External trace buffer command register
<tbd>
Table 23.
USART fractional generator divider value register (UARTFRGDIV, address 0x4004
80F0) bit description
Bit
Symbol
Description
Reset
value
7:0
DIV
Denominator of the fractional divider. DIV is equal to the programmed
value +1. Always set to 0xFF to use with the fractional baud rate
generator.
0
31:8
-
Reserved
-
Table 24.
USART fractional generator multiplier value register (UARTFRGMULT, address
0x4004 80F4) bit description
Bit
Symbol
Description
Reset
value
7:0
MULT
Numerator of the fractional divider. MULT is equal to the programmed
value.
0
31:8
-
Reserved
-
Table 25.
External trace buffer command register (EXTTRACECMD, address 0x4004 80FC)
bit description
Bit
Symbol
Description
Reset
value
0
START
Trace start command <tbd>
0
1
STOP
Trace stop command <tbd>
0
31:2
-
Reserved
0