Chapter 7 S12 Clock, Reset and Power Management Unit (S12CPMU_UHV_V5)
S12ZVHY/S12ZVHL Family Reference Manual, Rev. 1.05
264
Freescale
Semiconductor
7.3.2.17
Autonomous Clock Trimming Register (CPMUACLKTR)
The CPMUACLKTR register configures the trimming of the Autonomous Clock (ACLK - trimmable
internal RC-Oscillator) which can be selected as clock source for some CPMU features
.
Read: Anytime
Write: Anytime
Module Base + 0x0013
7
6
5
4
3
2
1
0
R
ACLKTR5
ACLKTR4
ACLKTR3
ACLKTR2
ACLKTR1
ACLKTR0
0
0
W
Reset
F
F
F
F
F
F
0
0
After de-assert of System Reset a value is automatically loaded from the Flash memory.
Figure 7-22. Autonomous Clock Trimming Register (CPMUACLKTR)
Table 7-20. CPMUACLKTR Field Descriptions
Field
Description
7–2
ACLKTR[5:0]
Autonomous Clock Period Trimming Bits
for trimming effects. The ACLKTR[5:0] value
represents a signed number influencing the ACLK period time.
Table 7-21. Trimming Effect of ACLKTR[5:0]
ACLKTR[5:0]
Decimal
ACLK frequency
100000
-32
lowest
100001
-31
increasing
....
111111
-1
000000
0
mid
000001
+1
increasing
....
011110
+30
011111
+31
highest
