AT90USB647-MU Atmel, AT90USB647-MU Datasheet - Page 49

• Manufacturer Part Number: AT90USB647-MU
• Description: MCU, 8BIT, 64K FLASH, USB, 64QFN
• Manufacturer: Atmel

Specifications of AT90USB647-MU

• Controller Family/series: AT90
• No. Of I/o's: 48
• Eeprom Memory Size: 2KB
• Ram Memory Size: 4KB
• Cpu Speed: 16MHz
• No. Of: RoHS Compliant
• Core Size: 8bit
• Program Memory Size: 64KB
• Oscillator Type: External, Internal
• Package: 64QFN EP
• Device Core: AVR
• Family Name: AT90
• Maximum Speed: 20 MHz
• Ram Size: 4 KB
• Operating Supply Voltage: 3.3|5 V
• Data Bus Width: 8 Bit
• Program Memory Type: Flash
• Number Of Programmable I/os: 48
• Interface Type: SPI/TWI/USART/USB
• On-chip Adc: 8-chx10-bit
• Operating Temperature: -40 to 85 °C
• Number Of Timers: 4
• Lead Free Status / Rohs Status: Details

6.10.2
7593K–AVR–11/09
PLL Control and Status Register – PLLCSR
Figure 6-4.
• Bit 7..5 – Res: Reserved Bits
These bits are reserved bits in the AT90USB64/128 and always read as zero.
• Bit 4..2 – PLLP2:0 PLL Prescaler
These bits allow to configure the PLL input prescaler to generate the 2MHz input clock for the
PLL.
Table 6-11.
Note:
XTAL1
XTAL2
Bit
$29 ($29)
Read/Write
Initial Value
PLLP2
0
0
0
0
1
1
1
1
1. For AT90USB128x only. Do not use with AT90USB64x.
2. For AT90USB64x only. Do not use with AT90USB128x.
RC OSCILLATOR
8 MHz
OSCILLATORS
0
7
R
PLL Clocking System
PLL input prescaler configurations
PLLP1
0
0
1
1
0
0
1
1
0
6
R
PLLP0
5
R
0
0
1
0
1
0
1
0
1
4
PLLP2
R/W
0
Clock Division
PLL clock
Prescaler
Reserved
Reserved
Reserved
Reserved
Reserved
Factor
8
8
3
PLLP1
R/W
0
4
(1)
(2)
clk
2
PLLP0
R/W
0
2MHz
External XTAL required for USB
AT90USB64/128
System Clock
PLLE
PLL
24x
1
PLLE
R/W
0/1
operation (MHz)
Detector
Lock
0
PLOCK
R/W
0
16
16
8
-
-
-
-
-
(1)
(2)
PLOCK
PLLCSR
(48MHz)
clk USB
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