AT91SAM9G45-EKES Atmel, AT91SAM9G45-EKES Datasheet - Page 837

• Manufacturer Part Number: AT91SAM9G45-EKES
• Description: KIT EVAL FOR AT91SAM9G45
• Manufacturer: Atmel
• Series: AT91SAM Smart ARMr
• Type: MCUr

Specifications of AT91SAM9G45-EKES

• Contents: Board
• Processor To Be Evaluated: SAM9G45
• Data Bus Width: 32 bit
• Interface Type: I2C, SPI, UART
• Maximum Operating Temperature: + 50 C
• Minimum Operating Temperature: - 10 C
• Operating Supply Voltage: 1.8 V to 3.3 V
• For Use With/related Products: AT91SAM9G45
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: Q4626953

837
AT91SAM9G45
The auto-valid-bank mechanism allows the transfer of data (IN & OUT) without the intervention
of the CPU. This means that bank validation (set TX_PK_RDY or clear the RX_BK_RDY bit) is
done by hardware.
A transfer descriptor can be used. Instead of programming the register directly, a descriptor
s h o u l d b e p r o g r a m m e d a n d t h e a d d r e s s o f t h i s d e s c r i p t o r i s t h e n g i v e n t o
UDPHS_DMANXTDSC to be processed after setting the LDNXT_DSC field (Load Next Descrip-
tor Now) in UDPHS_DMACONTROLx register.
The structure that defines this transfer descriptor must be aligned.
Each buffer to be transferred must be described by a DMA Transfer descriptor (see
DMA Channel Transfer Descriptor” on page
cuting transfer of the buffer, the UDPHS may fetch a new transfer descriptor from the memory
address pointed by the UDPHS_DMANXTDSCx register. Once the transfer is complete, the
transfer status is updated in the UDPHS_DMASTATUSx register.
To chain a new transfer descriptor with the current DMA transfer, the DMA channel must be
stopped. To do so, INTDIS_DMA and TX_BK_RDY may be set in the UDPHS_EPTCTLENBx
register. It is also possible for the application to wait for the completion of all transfers. In this
case the LDNXT_DSC field in the last transfer descriptor UDPHS_DMACONTROLx register
must be set to 0 and CHANN_ENB set to 1.
Then the application can chain a new transfer descriptor.
The INTDIS_DMA can be used to stop the current DMA transfer if an enabled interrupt is trig-
gered. This can be used to stop DMA transfers in case of errors.
The application can be notified at the end of any buffer transfer (ENB_BUFFIT bit in the
UDPHS_DMACONTROLx register).
– Size of buffer to send: size of the buffer to be sent to the host.
– END_B_EN: The endpoint can validate the packet (according to the values
– END_BUFFIT: generate an interrupt when the BUFF_COUNT in
– CHANN_ENB: Run and stop at end of buffer
programmed in the AUTO_VALID and SHRT_PCKT fields of UDPHS_EPTCTLx.)
(See
with
UDPHS_DMASTATUSx reaches 0.
DMA)
“UDPHS Endpoint Control Register” on page 876
887). Transfer descriptors are chained. Before exe-
and
Figure 38-12. Autovalid
6438F–ATARM–21-Jun-10
“UDPHS