ATMEGA16U2-16AU Atmel, ATMEGA16U2-16AU Datasheet - Page 40

• Manufacturer Part Number: ATMEGA16U2-16AU
• Description: 8-bit Microcontrollers - MCU 16K Flash
• Manufacturer: Atmel

Specifications of ATMEGA16U2-16AU

• Product Category: 8-bit Microcontrollers - MCU
• Rohs: yes
• Core: AVR
• Data Bus Width: 8 bit
• Program Memory Size: 16 KB
• Data Ram Size: 1.25 KB
• Data Rom Size: 512 B
• Program Memory Type: Flash
• Factory Pack Quantity: 1250

8.11.6
7799D–AVR–11/10
PLLCSR – PLL Control and Status Register
Table 8-9.
• Bit 7:5 – Res: Reserved Bits
These bits are reserved bits in the ATmega8U2/16U2/32U2 and always read as zero.
• Bit 4 – DIV5 PLL Input Prescaler (1:5)
• Bit 3 – DIV3 PLL Input Prescaler (1:3)
• Bit 2 – PINDIV PLL Input Prescaler (1:1, 1:2)
These bits allow to configure the PLL input prescaler to generate the 8MHz input clock for the
PLL from either a 8 or 16 MHz input.
When using a 8 MHz clock source, this bit must be set to 0 before enabling PLL (1:1).
When using a 16 MHz clock source, this bit must be set to 1 before enabling PLL (1:2).
• Bit 3:2 – Res: Reserved Bits
These bits are reserved and always read as zero.
Bit
0x29 (0x49)
Read/Write
Initial Value
CLKPS3
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
Clock Prescaler Select
R
7
–
0
CLKPS2
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
R
6
–
0
CLKPS1
R
5
–
0
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
DIV5
R/W
4
0
CLKPS0
ATmega8U2/16U2/32U2
DIV3
R
3
0
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
PINDIV
R
2
0
Clock Division Factor
PLLE
R/W
1
0
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
PLOCK
128
256
16
32
64
1
2
4
8
R
0
0
PLLCSR
40