LPC1767FBD100,551 NXP Semiconductors, LPC1767FBD100,551 Datasheet - Page 265

• Manufacturer Part Number: LPC1767FBD100,551
• Description: IC ARM CORTEX MCU 512K 100-LQFP
• Manufacturer: NXP Semiconductors
• Series: LPC17xxr

Specifications of LPC1767FBD100,551

• Core Processor: ARM® Cortex-M3™
• Core Size: 32-Bit
• Speed: 100MHz
• Connectivity: Ethernet, I²C, IrDA, Microwire, SPI, SSI, UART/USART
• Peripherals: Brown-out Detect/Reset, DMA, I²S, Motor Control PWM, POR, PWM, WDT
• Number Of I /o: 70
• Program Memory Size: 512KB (512K x 8)
• Program Memory Type: FLASH
• Ram Size: 64K x 8
• Voltage - Supply (vcc/vdd): 2.4 V ~ 3.6 V
• Data Converters: A/D 8x12b, D/A 1x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 100-LQFP
• Processor Series: LPC17
• Core: ARM Cortex M3
• 3rd Party Development Tools: MDK-ARM, RL-ARM, ULINK2, MCB1760, MCB1760U, MCB1760UME
• For Use With: 622-1005 - USB IN-CIRCUIT PROG ARM7 LPC2K
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / Rohs Status: Details
• Other names: 568-4967; 935289808551

NXP Semiconductors
UM10360
User manual
11.15.7.1 Setting up the DMA transfer
11.15.7.2 Finding the DMA Descriptor
11.15.7.3 Transferring the Data
In ATLE mode, the last buffer length to be transferred always ends with a short or empty
packet indicating the end of the USB transfer. If the concatenated transfer lengths are
such that the USB transfer ends on a MaxPacketSize packet boundary, the (NDIS) host
will send an empty packet to mark the end of the USB transfer.
IN transfers in ATLE mode
For IN USB transfers from the device to the host, DMA_buffer_length is set by the device
software as in normal mode.
In ATLE mode, the device concatenates data from multiple DDs to form a single USB
transfer. If a DD is retired in the middle of a packet (packet size is less than
MaxPacketSize), the next DD referenced by Next_DD_pointer is fetched, and the
remaining bytes to form a packet of MaxPacketSize are transferred from the next DD’s
buffer.
If the next DD is not programmed (i.e. Next_DD_valid field in DD is 0), and the DMA buffer
length for the current DD has completed before the MaxPacketSize packet boundary, then
the available bytes from current DD are sent as a short packet on USB, which marks the
end of the USB transfer for the host.
If the last buffer length completes on a MaxPacketSize packet boundary, the device
software must program the next DD with DMA_buffer_length field 0, so that an empty
packet is sent by the device to mark the end of the USB transfer for the host.
For OUT endpoints, the host hardware needs to set the field Message_length_position in
the DD. This indicates the start location of the message length in the incoming data
packets. Also the device software has to set the DMA_buffer_length field to 0 for OUT
endpoints because this field is updated by the device hardware after the extraction of the
buffer length.
For IN endpoints, descriptors are set in the same way as in normal mode operation.
Since a single packet can be split between two DDs, software should always keep two
DDs ready, except for the last DMA transfer which ends with a short or empty packet.
DMA descriptors are found in the same way as the normal mode operation.
OUT endpoints
If the LS_byte_extracted or MS_byte_extracted bit in the status field is not set, the
hardware will extract the transfer length from the data stream and program
DMA_buffer_length. Once the extraction is complete both the LS_byte_extracted and
MS_byte_extracted bits will be set.
IN endpoints
The DMA transfer proceeds as in normal mode and continues until the number of bytes
transferred equals the DMA_buffer_length.
All information provided in this document is subject to legal disclaimers.
Rev. 2 — 19 August 2010
Chapter 11: LPC17xx USB device controller
UM10360
© NXP B.V. 2010. All rights reserved.
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