UM10208_2
© NXP B.V. 2007. All rights reserved.
User manual
Rev. 02 — 1 June 2007
241 of 362
NXP Semiconductors
UM10208
Chapter 17: LPC2800 USB Device
8.41 USB DMA Channel Source Address Registers (UDMA0Src -
0x8004 0008 and UDMA1Src - 0x8004 0048)
Writing to this register while the USB DMA channel is enabled will stop the channel and
set its status (error) field to Update Error.
8.42 USB DMA Channel Destination Address Registers (UDMA0Dest -
0x8004 000C and UDMA1Dest - 0x8004 004C)
Writing this register while the USB DMA channel is enabled will stop the channel and set
its status (error) field to Update Error.
8.43 USB DMA Channel Count Registers (UDMA0Cnt - 0x8004 0014,
UDMA1Cnt - 0x8004 0054)
Writing this register while the USB DMA channel is enabled will stop the channel and set
its status (error) field to Update Error.
Table 270. USB DMA Channel Source Address Registers (UDMA0Src - 0x8004 0008 and
UDMA1Src - 0x8004 0048)
Bit
Symbol
Description
Reset
value
31:0
Source
Address
0x0000 0004 for a Endpoint 1 OUT (RX) transfer
0x0000 0008 for a Endpoint 2 OUT (RX) transfer
Memory address for an IN (TX) transfer (bits 1:0 must be 00 or a
Configuration Error results)
For an IN (TX) transfer, reading this register returns the word
address just above the last data that was successfully read. This is
true both during the transfer and after it completes.
0
Table 271. USB DMA Channel Destination Address Registers (UDMA0Dest - 0x8004 000C
and UDMA1Dest - 0x8004 004C)
Bit
Symbol
Description
Reset
value
31:0
Destination
Address
0x0000 0004 for a Endpoint 1 IN (TX) transfer
0x0000 0008 for a Endpoint 2 IN (TX) transfer
Memory address for an OUT (RX) transfer (bits 1:0 must be 00 or a
Configuration Error results)
For an OUT (RX) transfer, reading this register returns the word
address just above the last data that was successfully written. This
is true both during the transfer and after it completes.
0
Table 272. USB DMA Channel Count Registers (UDMA0Dest - 0x8004 0014 and UDMA1Dest -
0x8004 0054
Bit
Symbol
Description
Reset
value
31:0
TCOUNT
Write this register with the number of bytes the USB DMA channel
is to transfer.
Reading this register while the channel is enabled/operating
returns the number of bytes still to be read.
Reading this register after the transfer has ended returns the
number of bytes that were not written.
0