SAM7X256 Atmel Corporation, SAM7X256 Datasheet - Page 459

• Manufacturer Part Number: SAM7X256
• Manufacturer: Atmel Corporation

Specifications of SAM7X256

• Flash (kbytes): 256 Kbytes
• Pin Count: 100
• Max. Operating Frequency: 55 MHz
• Cpu: ARM7TDMI
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 62
• Ext Interrupts: 62
• Usb Transceiver: 1
• Usb Speed: Full Speed
• Usb Interface: Device
• Spi: 2
• Twi (i2c): 1
• Uart: 3
• Can: 1
• Ssc: 1
• Ethernet: 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 8
• Adc Resolution (bits): 10
• Adc Speed (ksps): 384
• Resistive Touch Screen: No
• Temp. Sensor: No
• Crypto Engine: No
• Sram (kbytes): 64
• Self Program Memory: NO
• Dram Memory: No
• Nand Interface: No
• Picopower: No
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 3.3
• Operating Voltage (vcc): 3.0 to 3.6
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 3
• Output Compare Channels: 3
• Input Capture Channels: 3
• Pwm Channels: 4
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: No

6120I–ATARM–06-Apr-11
banks of memory are used. While one is available for the microcontroller, the other one is locked
by the USB device.
Figure 34-10. Bank Swapping in Data OUT Transfers for Ping-pong Endpoints
When using a ping-pong endpoint, the following procedures are required to perform Data OUT
transactions:
1. The host generates a Data OUT packet.
2. This packet is received by the USB device endpoint. It is written in the endpoint’s FIFO
3. The USB device sends an ACK PID packet to the host. The host can immediately send
4. The microcontroller is notified that the USB device has received a data payload, polling
5. The number of bytes available in the FIFO is made available by reading RXBYTECNT
6. The microcontroller transfers out data received from the endpoint’s memory to the
7. The microcontroller notifies the USB peripheral device that it has finished the transfer
8. A third Data OUT packet can be accepted by the USB peripheral device and copied in
9. If a second Data OUT packet has been received, the microcontroller is notified by the
10. The microcontroller transfers out data received from the endpoint’s memory to the
Bank 0.
a second Data OUT packet. It is accepted by the device and copied to FIFO Bank 1.
RX_DATA_BK0 in the endpoint’s UDP_ CSRx register. An interrupt is pending for this
endpoint while RX_DATA_BK0 is set.
in the endpoint’s UDP_ CSRx register.
microcontroller’s memory. Data received is made available by reading the endpoint’s
UDP_ FDRx register.
by clearing RX_DATA_BK0 in the endpoint’s UDP_ CSRx register.
the FIFO Bank 0.
flag RX_DATA_BK1 set in the endpoint’s UDP_ CSRx register. An interrupt is pending
for this endpoint while RX_DATA_BK1 is set.
microcontroller’s memory. Data received is available by reading the endpoint’s UDP_
FDRx register.
1 st Data Payload
2 nd Data Payload
3 rd Data Payload
Microcontroller
Write and Read at the Same Time
Bank 0
Endpoint 1
Bank 1
Endpoint 1
Bank 0
Endpoint 1
Write
USB Device
Bank 0
Endpoint 1
Bank 1
Endpoint 1
Bank 0
Endpoint 1
Read
SAM7X512/256/128
USB Bus
2 nd Data Payload
3 rd Data Payload
1 st Data Payload
Data IN Packet
Data IN Packet
Data IN Packet
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