Chapter 9 Clocks and Reset Generator (CRGV4) Block Description
256
MC9S12C-Family / MC9S12GC-Family
Freescale Semiconductor
Rev 01.24
9.3.2.1
CRG Synthesizer Register (SYNR)
The SYNR register controls the multiplication factor of the PLL. If the PLL is on, the count in the loop
divider (SYNR) register effectively multiplies up the PLL clock (PLLCLK) from the reference frequency
by 2 x (SYNR+1). PLLCLK will not be below the minimum VCO frequency (f
SCM
).
NOTE
If PLL is selected (PLLSEL=1), Bus Clock = PLLCLK / 2
Bus Clock must not exceed the maximum operating system frequency.
Read: anytime
Write: anytime except if PLLSEL = 1
NOTE
Write to this register initializes the lock detector bit and the track detector
bit.
0x000B
ARMCOP
R
0
0
0
0
0
0
0
0
W
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Module Base + 0x0000
7
6
5
4
3
2
1
0
R
0
0
SYN5
SYNR
SYN3
SYN2
SYN1
SYN0
W
Reset
0
0
0
0
0
0
0
0
= Unimplemented or Reserved
Figure 9-4. CRG Synthesizer Register (SYNR)
Register
Name
Bit 7
6
5
4
3
2
1
Bit 0
= Unimplemented or Reserved
Figure 9-3. CRG Register Summary (continued)
PLLCLK
2xOSCCLKx
SYNR
1
+
(
)
REFDV
1
+
(
)
----------------------------------
=
Summary of Contents for MC9S12C Family
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