FLL+ Clock Module Operation
5-10
FLL+ Clock Module
5.2.6
DCO Modulator
The modulator mixes two adjacent DCO frequencies to produce an
intermediate effective frequency and spread the clock energy, reducing
electromagnetic interference (EMI)
.
The modulator mixes the two adjacent
frequencies across 32 DCOCLK clock cycles.
The error of the effective frequency is zero every 32 DCOCLK cycles and does
not accumulate. The modulator settings and DCO control are automatically
controlled by the FLL hardware. Figure 5−4 illustrates the modulator
operation.
Figure 5−4. Modulator Patterns
Lower DCO Tap Frequency f
DCO
31
24
16
15
5
4
3
2
1
0
Upper DCO Tap Frequency f
DCO+1
One ACLK Cycle
f
(DCOCLK)
Cycles, Shown for f(DCOCLK)=f(ACLK)
×
32
N
DCOmod
Summary of Contents for MSP430x4xx Family
Page 1: ...MSP430x4xx Family 2007 Mixed Signal Products User s Guide SLAU056G ...
Page 2: ......
Page 6: ...vi ...
Page 114: ...3 76 RISC 16 Bit CPU ...
Page 304: ...5 20 FLL Clock Module ...
Page 340: ...7 8 Supply Voltage Supervisor ...
Page 348: ...8 8 16 Bit Hardware Multiplier ...
Page 372: ...9 24 32 Bit Hardware Multiplier ...
Page 400: ...10 28 DMA Controller ...
Page 428: ...13 10 Basic Timer1 ...
Page 466: ...15 24 Timer_A ...
Page 522: ...17 30 USART Peripheral Interface UART Mode ...
Page 544: ...18 22 USART Peripheral Interface SPI Mode ...
Page 672: ...23 12 Comparator_A ...
Page 692: ...24 20 LCD Controller ...
Page 746: ...26 28 ADC12 ...