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6.6.9 PLL Post-Divider Control Register (POSTDIV)
PLL Controller Register Map
The PLL post-divider control register (POSTDIV) is shown in
and described in
for
PLLC1 and PLLC2. POSTDIV is a read only register. The post divider ratio for PLLC1 may be changed by
the bit PLL1_POSTDIV in the miscellaneous control register (MISC) in the System Control module. See
for a description of MISC register. By default, PLL1_POSTDIV is configured such that the
post divider is equal to 2. Therefore, in order to enable higher frequences, you must change bit
PLL1_POSTDIV such that the post divider is equal to 1. But if DEV_SPEED is 1 or 3, it is not possible to
change the post divider from the default value of 2, and thus the frequencies are limited. The post divider
for PLLC2 is always fixed (cannot be changed) to 1.
Figure 6-11. PLL Post-Divider Control Register (POSTDIV)
31
16
Reserved
R-0
R-0
15
14
5
4
0
POSTDEN
Reserved
RATIO
R-1
R-0
R-1
R-1
R-0
R-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 6-12. PLL Post-Divider Control (POSTDIV) Field Descriptions
Bit
Field
Value
Description
31-16
Reserved
Reserved
15
POSTDEN
Post-divider enable. This bit must always be set to 1.
0
Disable
1
Enable
14-5
Reserved
0
Reserved
4-0
RATIO
Divider ratio for post divider. Ratio value = RATIO + 1
SPRUFB3 – September 2007
PLL Controllers (PLLCs)
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