atmega32u4-16mu ATMEL Corporation, atmega32u4-16mu Datasheet - Page 40

• Manufacturer Part Number: atmega32u4-16mu
• Description: Atmega32u4 8-bit Avr Microcontroller With 32k Bytes Of Isp Flash And Usb Controller
• Manufacturer: ATMEL Corporation

40
ATmega32U4
Figure 6-5.
• Bit 3..0 – PDIV3:0 PLL Lock Frequency
These bits configure the PLL internal VCO clock reference according to the required output fre-
quency value.
• The optimal PLL configuration at 5V is: PLL output frequency = 96 MHz, divided by 1.5
Fi
Fi x ---
PDIV3
to generate the 64 MHz High Speed Timer clock, and divided by 2 to generate the 48
MHz USB clock.
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
2
3
PDIV2
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
PLL Postcaler operation with division factor = 1.5
PDIV1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
PDIV0
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
PLL Output Frequency
Not allowed
Not allowed
Not allowed
Not allowed
Not allowed
Not allowed
Not allowed
32 MHz
40 MHz
48 MHz
56 MHz
64 MHz
72 MHz
80 MHz
88 MHz
96 MHz
7766A–AVR–03/08