ATMEGA16U2-MU Atmel, ATMEGA16U2-MU Datasheet - Page 28

• Manufacturer Part Number: ATMEGA16U2-MU
• Description: MCU AVR 16K FLASH USB 32-VQFN
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA16U2-MU

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 16MHz
• Connectivity: SPI, UART/USART, USB
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 22
• Program Memory Size: 16KB (8K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 512 x 8
• Ram Size: 512 x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 32-VQFN Exposed Pad, 32-HVQFN, 32-SQFN, 32-DHVQFN
• Core: AVR8
• Processor Series: ATMEGA16x
• Data Bus Width: 8 bit
• Maximum Clock Frequency: 16 MHz
• Data Ram Size: 1.25 KB
• Data Rom Size: 512 B
• Number Of Programmable I/os: 22
• Number Of Timers: 2
• Mounting Style: SMD/SMT
• Height: 0.95 mm
• Interface Type: SPI, UART
• Length: 5 mm
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Supply Voltage (max): 5.5 V
• Supply Voltage (min): 2.7 V
• Width: 5 mm
• For Use With: ATSTK600 - DEV KIT FOR AVR/AVR32ATSTK500 - PROGRAMMER AVR STARTER KIT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Data Converters: -
• Lead Free Status / Rohs Status: Details

8.2.2
8.2.2.1
8.2.2.2
7799D–AVR–11/10
USB
CPU Clock
External
Oscillator
RC oscillator
Clock switch Algorythm
Swith from external clock to RC clock
Switch from RC clock to external clock
non-Idle
Figure 8-3.
if (Usb_suspend_detected())
{
}
if (Usb_wake_up_detected())
{
}
Usb_ack_suspend();
Usb_freeze_clock();
Disable_pll();
Enable_RC_clock();
while (!RC_clock_ready());
Select_RC_clock();
Disable_external_clock();
Usb_ack_wake_up();
Enable_external_clock();
while (!External_clock_ready()); // while (CLKSTA.EXTON != 1);
Select_external_clock();
Enable_pll();
Disable_RC_clock();
while (!Pll_ready());
Usb_unfreeze_clock();
Ext
3ms
Idle
Example of clock switching with wake-up from Device
Watchdog wake-up
from power-down
(Suspend)
2 Upstream Resume from device
RC
// if (UDINT.SUSPI == 1)
// UDINT.SUSPI = 0;
// USBCON.FRZCLK = 1;
// PLLCSR.PLLE = 0;
// CLKSEL0.RCE = 1;
// while (CLKSTA.RCON != 1);
// CLKSEL0.CLKS = 0;
// CLKSEL0.EXTE = 0;
// if (UDINT.WAKEUPI == 1)
// UDINT.WAKEUPI = 0;
// CKSEL0.EXTE = 1;
// CLKSEL0.CLKS = 1;
// PLLCSR.PLLE = 1;
// CLKSEL0.RCE = 0;
// while (PLLCSR.PLOCK != 1);
// USBCON.FRZCLK = 0;
ATmega8U2/16U2/32U2
upstream-resume
2
non-Idle
Ext
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