AT90USB162-16MU Atmel, AT90USB162-16MU Datasheet - Page 27

• Manufacturer Part Number: AT90USB162-16MU
• Description: MCU AVR USB 16K FLASH 32-QFN
• Manufacturer: Atmel
• Series: AVR® 90USBr

Specifications of AT90USB162-16MU

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 16MHz
• Connectivity: EBI/EMI, PS/2, SPI, UART/USART, USB
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 22
• Program Memory Size: 16KB (16K x 8)
• 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-TQFN
• Controller Family/series: AVR USB
• No. Of I/o's: 22
• Eeprom Memory Size: 512Byte
• Ram Memory Size: 512Byte
• Cpu Speed: 16MHz
• Rohs Compliant: Yes
• Processor Series: AT90USBx
• Core: AVR8
• Data Bus Width: 8 bit
• Data Ram Size: 512 B
• Interface Type: SPI, USART, debugWIRE
• Maximum Clock Frequency: 16 MHz
• Number Of Programmable I/os: 22
• Number Of Timers: 2
• Operating Supply Voltage: 2.7 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: EWAVR, EWAVR-BL
• Development Tools By Supplier: ATAVRDRAGON, ATSTK500, ATSTK600, ATSTK525, ATSTK526, ATAVRISP2, ATAVRONEKIT, AT90USBKEY, ATEVK525
• Minimum Operating Temperature: - 40 C
• For Use With: ATSTK600 - DEV KIT FOR AVR/AVR32ATSTK526 - KIT STARTER FOR AT90USB82/162ATAVRDRAGON - KIT DRAGON 32KB FLASH MEM AVRATSTK525 - KIT STARTER FOR AT90USBAT90USBKEY2 - KIT DEMO FOR AT90USB
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Data Converters: -
• Lead Free Status / Rohs Status: Details

Clock switch
Algorythm
Swith from external
clock to RC clock
Switch from RC clock to
external clock
Clock Selection
Register 0 – CLKSEL0
7707A–AVR–01/07
• Bit 7-6 – RCSUT[1:0]: SUT for RC oscillator
These 2 bits are the SUT value for the RC Oscillator. If the RC oscillator is selected by fuse bits,
the SUT fuse are copied into these bits. A firmware change will not have any effect because this
additionnal start-up time is only used after a reset and not after a clock switch.
• Bit 5-4 – EXSUT[1:0]: SUT for External Oscillator / Low Power Oscillator
These 2 bits are the SUT value for the External Oscillator / Low Power Oscillator. If the External
oscillator / Low Power Oscillator is selected by fuse bits, the SUT fuse are copyed into these
bits. The firmware can modify these bits by writing a new value. This value will be used at the
next start of the External Oscillator / Low Power Oscillator.
• Bit 3 – RCE: Enable RC Oscillator
The RCE bit must be written to logic one to enable the RC Oscillator. The RCE bit must be writ-
ten to logic zero to disable the RC Oscillator.
• Bit 2 – EXTE: Enable External Oscillator / Low Power Oscillator
Bit
Read/Write
Initial Value
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();
7
RCSUT
1
R/W
0
6
RCSUT
0
R/W
0
5
EXSUT
1
R/W
0
4
EXSUT
0
R/W
0
3
RCE
R/W
See Bit Description
// 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;
2
EXTE
R/W
1
-
R
0
CLKS
R/W
CLKSEL
0
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