AT90USB647-MU Atmel, AT90USB647-MU Datasheet - Page 251

• 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

21.4
21.4.1
21.4.2
7593K–AVR–11/09
General Operating Modes
Introduction
Power-on and reset
After a hardware reset, the USB controller is disabled. When enabled, the USB controller has to
run the Device Controller or the Host Controller. This is performed using the USB ID detection.
The software anyway has to select the mode (Host, Device) in order to access to the Device
controller registers or to the Host controller registers, which are multiplexed. For example, even
if the USB controller has detected a Device mode (pin ID high), the software shall select the
device mode (bit HOST cleared), otherwise it will access to the host registers. This is also true
for the Host mode.
Note:
The next diagram explains the USB controller main states on power-on:
Figure 21-9. USB controller states after reset
USB Controller state after an hardware reset is ‘Reset’. In this state:
After setting USBE, the USB Controller enters in the Host or in the Device state (according to the
USB ID pin). The selected controller is ‘Idle’.
The USB Controller can at any time be ‘stopped’ by clearing USBE. In fact, clearing USBE acts
as an hardware reset.
• If the ID pin is not connected to ground, the USB ID bit is set by hardware (internal pull up on
• The ID bit is cleared by hardware when a low level has been detected on the ID pin. The
• USBE is not set
• the USB controller clock is stopped in order to minimize the power consumption
• the USB controller is disabled,
• the USB pad is in the suspend mode,
• the Host and Device USB controllers internal states are reset.
the UID pad) and the USB Device controller is selected.
Device controller is then disabled and the Host controller enabled.
(FRZCLK=1),
For the AT90USB646/1286 products the Host mode is not included in the USB controller, and the
ID pin is not used and should be configured and used as a general I/O.
AT90USB646/1286 forced mode
Clock stopped
Device
FRZCLK=1
M acro off
USBE=1
ID=1
USBE=0
Reset
USBE=1
ID=0
AT90USB647/1287 only
USBE=0
RESET
USBE=0
Host
HW
USBE=0
<any other
state>
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