SAM3S1A Atmel Corporation, SAM3S1A Datasheet - Page 933

• Manufacturer Part Number: SAM3S1A
• Manufacturer: Atmel Corporation

Specifications of SAM3S1A

• Flash (kbytes): 64 Kbytes
• Pin Count: 48
• Max. Operating Frequency: 64 MHz
• Cpu: Cortex-M3
• # Of Touch Channels: 17
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 34
• Ext Interrupts: 34
• Usb Transceiver: 1
• Quadrature Decoder Channels: 1
• Usb Speed: Full Speed
• Usb Interface: Device
• Spi: 2
• Twi (i2c): 2
• Uart: 3
• Ssc: 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 8
• Adc Resolution (bits): 12
• Adc Speed (ksps): 1000
• Analog Comparators: 1
• Resistive Touch Screen: No
• Temp. Sensor: Yes
• Crypto Engine: No
• Sram (kbytes): 16
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: Yes
• Picopower: No
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 1.8/3.3
• Operating Voltage (vcc): 1.62 to 3.6
• Fpu: No
• Mpu / Mmu: Yes / No
• Timers: 3
• Output Compare Channels: 3
• Input Capture Channels: 3
• Pwm Channels: 4
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

Figure 37-6. Data IN Transfer for Non Ping-pong Endpoint
Figure 37-7. Bank Swapping Data IN Transfer for Ping-pong Endpoints
6500C–ATARM–8-Feb-11
USB Bus Packets
TXPKTRDY Flag
(UDP_CSRx)
TXCOMP Flag
(UDP_CSRx)
FIFO (DPR)
Content
Using Endpoints With Ping-pong Attribute
Set by the firmware
Data IN
PID
Microcontroller
1 st Data Payload
2 nd Data Payload
3 rd Data Payload
Prevous Data IN TX
Data IN 1
Interrupt Pending
The use of an endpoint with ping-pong attributes is necessary during isochronous transfer. This
also allows handling the maximum bandwidth defined in the USB specification during bulk trans-
fer. To be able to guarantee a constant or the maximum bandwidth, the microcontroller must
prepare the next data payload to be sent while the current one is being sent by the USB device.
Thus two banks of memory are used. While one is available for the microcontroller, the other
one is locked by the USB device.
Cleared by Hw
Data IN 1
DPR access by the firmware
Bank 0
Endpoint 1
Bank 1
Endpoint 1
Bank 0
Endpoint 1
ACK
PID
Load In Progress
Write
Set by the firmware
Microcontroller Load Data in FIFO
USB Device
PID
Data IN
Bank 0
Endpoint 1
Bank 1
Endpoint 1
Bank 0
Endpoint 1
Read
Read and Write at the Same Time
NAK
PID
Cleared by Firmware
PID
DPR access by the hardware
Data IN
USB Bus
Data is Sent on USB Bus
Data IN 2
2 nd Data Payload
3 rd Data Payload
1 st Data Payload
Data IN Packet
Data IN Packet
Data IN Packet
Payload in FIFO
Data IN 2
Cleared by Hw
SAM3S
ACK
PID
Cleared by
Firmware
Interrupt
Pending
933