ATSAM3U-EK Atmel, ATSAM3U-EK Datasheet - Page 954

• Manufacturer Part Number: ATSAM3U-EK
• Description: KIT EVAL FOR AT91SAM3U CORTEX
• Manufacturer: Atmel
• Type: MCUr

Specifications of ATSAM3U-EK

• Contents: Board
• Processor To Be Evaluated: SAM3U
• Data Bus Width: 32 bit
• Interface Type: RS-232, USB
• Operating Supply Voltage: 3 V
• Silicon Manufacturer: Atmel
• Core Architecture: ARM
• Core Sub-architecture: Cortex - M3
• Silicon Core Number: SAM3U4E
• Silicon Family Name: SAM3U
• Kit Contents: Board CD Docs
• Rohs Compliant: Yes
• For Use With/related Products: AT91SAM3U
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

39.6.8.5
954
954
SAM3U Series
SAM3U Series
Bulk IN or Interrupt IN: Sending a Packet Under Application Control (Device to Host)
The application can write one or several banks.
A simple algorithm can be used by the application to send packets regardless of the number of
banks associated to the endpoint.
Algorithm Description for Each Packet:
The application is notified that it is possible to write a new packet to the DPR by the
TX_PK_RDY interrupt. This interrupt can be enabled or masked by setting the TX_PK_RDY bit
in the UDPHS_EPTCTLENB/UDPHS_EPTCTLDIS register.
Algorithm Description to Fill Several Packets:
Using the previous algorithm, the application is interrupted for each packet. It is possible to
reduce the application overhead by writing linearly several banks at the same time. The
AUTO_VALID bit in the UDPHS_EPTCTLx must be set by writing the AUTO_VALID bit in the
UDPHS_EPTCTLENBx register.
The auto-valid-bank mechanism allows the transfer of data (IN and OUT) without the interven-
tion of the CPU. This means that bank validation (set TX_PK_RDY or clear the RX_BK_RDY bit)
is done by hardware.
The application is notified that all banks are free, so that it is possible to write another burst of
packets by the BUSY_BANK interrupt. This interrupt can be enabled or masked by setting the
BUSY_BANK flag in the UDPHS_EPTCTLENB and UDPHS_EPTCTLDIS registers.
This algorithm must not be used for isochronous transfer. In this case, the ping-pong mechanism
does not operate.
A Z e r o L e n g t h P a c k e t c a n b e s e n t b y s e t t i n g j u s t t h e T X _ P K T R D Y f l a g i n t h e
UDPHS_EPTSETSTAx register.
• The application waits for TX_PK_RDY flag to be cleared in the UDPHS_EPTSTAx register
• The application writes one USB packet of data in the DPR through the
• The application sets TX_PK_RDY flag in the UDPHS_EPTSETSTAx register.
• The application checks the BUSY_BANK_STA field in the UDPHS_EPTSTAx register. The
• The application writes a number of bytes inferior to the number of free DPR banks for the
• If the last packet is incomplete (i.e., the last byte of the bank has not been written) the
before it can perform a write access to the DPR.
memory window.
application must wait that at least one bank is free.
endpoint. Each time the application writes the last byte of a bank, the TX_PK_RDY signal is
automatically set by the UDPHS.
application must set the TX_PK_RDY bit in the UDPHS_EPTSETSTAx register.
64
KB endpoint logical
6430D–ATARM–25-Mar-11
6430D–ATARM–25-Mar-11