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Chapter 4
Clock Generator
Preliminary User’s Manual U17566EE1V2UM00
4.1.1
Description
The clock generator is built up as illustrated in the following figure.
Figure 4-1
Block diagram of the Clock Generator
The left-hand side of the figure shows how the three oscillators can be
connected to the CPU, the two PLLs, and to certain peripheral modules.
Software-controlled selectors allow you to specify the signal paths.
PLL
The integrated PLL synthesizer multiplies the frequency of the main oscillator
by eight. This yields a frequency of 32 MHz. The CPU can use the PLL output
directly. The output frequency of the PLL divided by two can supply the
peripherals of the microcontroller and also the CPU.
SSCG
The spread spectrum clock generator (SSCG) can generate a frequency-
modulated clock (modulation frequency and width can be chosen) that helps to
eliminate electromagnetic interference (EMI). The SSCG includes a
programmable frequency multiplier/divider that can multiply the frequency of
the main oscillator by up to 16.
The SSCG can supply the CPU system.
Standby
PRS0
AFCAN
UARTA
CSIB
TMZ
TMP
WCT
SG
Standby
PCLK2
PCLK3
.......
PCLK15
Standby
Standby
Standby
Stepper C/D
TMG
CSIB
LCD I/F
LCD C/D
ADC
Standby
Standby
Standby
FOUTCLK
FCC.FOEN
n=1,2,4,8,16,32,
64,128
n=1,2,4,8,16,32,64,128
1
0
TCC.WTSEL1
FCC.FOCKS[1:0]
PCC.SOSCP
PSM.CMODE
ICC.IICSEL1
CKC.PERIC
1
0
WCC.WDTSEL0
WCC.SOSCW
FCC.FOSOS
1
0
1
0
1
0
0
1
TCC.WTPS[2:0]
Watch Timer
/2
Watchdog
Timer
PCLK0
/2
/
.......
/
0
2
2
1
13
SPCLK0
SPCLK1
Standby
PRS1
Standby
SPCLK2
SPCLK3
.......
SPCLK15
/2
/
.......
/
0
2
2
1
13
n=1,2,3,4,6,8
IIC
Watch
Calibration
Timer
IICLK
WTCLK
LCDCLK
WDTCLK
PCLK1
WCTCLK
PCLK1
1/2
1/2
LCD C/D
0
1
0
1
1/2
1/n
1/n
1/n
WCC.WPS[2:0]
SCC.SPSEL0
SCPS.VBSPS[2:0]
PCC.CKS[1:0]
PCC.CLS
Standby
VBCLK
CPU System
CKC.DEN
CKC.PLLEN
SCFC0,SCFC1,SCFMC
CKC.SCEN
PCC.FRC
PCC.MFRC
X1
X2
XT1
XT2
TCC.WTSOS
TCC.WTSEL0
PLL
x8
SSCG
0
1
0
1
0
1
MOCLK
ROCLK
SOCLK
SBCLK
PLLCLK
SSCCLK
MainOSC
4 MHz
RingOSC
~200 KHz
SubOSC
32 KHz
0
1
Port
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