Fujitsu MB96300 series Hardware Manual page 181

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"1/n divider" (PLL clock divider)
The "1/n divider" is controlled by the PMS[4:0] PLL clock Multiplier Select bits. It defines the frequency
multiplication value of the PLL clock multiplier circuit (relation between CLKMC and CLKPLL).
Multiplication values from 1 to 32 are available. However the minimum and maximum permitted
frequencies for CLKMC, CLKVCO and CLKPLL (->CLKS1/S2) must be adhered. Do not change the
setting of these bits after activation of the PLL.
■ Setting the VCO clock Multiplier Select bits VMS[2:0]
The "1/m divider" is programmable to keep the VCO in its operating range as specified in the datasheet for
a wide range of PLL clock frequencies. Write a value to the VMS[2:0] bits which results in a valid
CLKVCO clock frequency. The table below shows recommended settings for a 4MHz Main clock. For
other Main clock frequencies, it is necessary to adjust the VMS[2:0] setting based on the formula:
"CLKVCO = CLKMC * m * n" .
Table 6.4-1 Recommended settings for the PMS[3:0], VMS[2:0] bits (1/2)for CLKMC=4MHz
Main
Oscillation
frequency
CLKMC
4 MHz
4 MHz
4 MHz
4 MHz
4 MHz
4 MHz
4 MHz
4 MHz
4 MHz
4 MHz
4 MHz
4 MHz
4 MHz
4 MHz
4 MHz
4 MHz
4 MHz
4 MHz
4 MHz
4 MHz
4 MHz
Requested Setting for
PLL output PMS[4:0] bits
frequency (n division
CLKPLL value)
4 MHz "00000" (div 1)
8 MHz "00001" (div 2)
12 MHz "00010" (div 3)
16 MHz "00011" (div 4)
20 MHz "00100" (div 5)
24 MHz "00101" (div 6)
28 MHz "00110" (div 7)
32 MHz "00111" (div 8)
36 MHz "01000" (div 9)
40 MHz "01001" (div 10)
44 MHz "01010" (div 11)
48 MHz "01011" (div 12)
52 MHz "01100" (div 13)
56 MHz "01101" (div 14)
60 MHz "01110" (div 15)
64 MHz "01111" (div 16)
68 MHz "10000" (div 17)
72 MHz "10001" (div 18)
76 MHz "10010" (div 19)
80 MHz "10011" (div 20)
84 MHz "10100" (div 21)
Setting for VCO
VMS[2:0] bits output
(m division frequency
value) CLKVCO
"111" (div 16) 64 MHz
"101" (div 12) 96 MHz
"011" (div 8) 96 MHz
"010" (div 6) 96 MHz
"010" (div 6) 120 MHz
"001" (div 4) 96 MHz
"001" (div 4) 112 MHz
"001" (div 4) 128 MHz
"000" (div 2) 72 MHz
"000" (div 2) 80 MHz
"000" (div 2) 88 MHz
"000" (div 2) 96 MHz
"000" (div 2) 104 MHz
"000" (div 2) 112 MHz
"000" (div 2) 120 MHz
"000" (div 2) 128 MHz
"000" (div 2) 136 MHz
"000" (div 2) 144 MHz
"000" (div 2) 152 MHz
"000" (div 2) 160 MHz
"000" (div 2) 168 MHz
CHAPTER 6 CLOCKS
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