Usb Ep Dma Status Register (Usbepdmast - 0Xe009 0084); Usb Ep Dma Enable Register (Usbepdmaen - 0Xe009 0088); Usb Ep Dma Disable Register (Usbepdmadis - 0Xe009 008C) - Philips LPC214 Series User Manual

Philips Semiconductors
Volume 1

14.8.15 USB EP DMA Status register (USBEpDMASt - 0xE009 0084)

This register indicates whether the DMA for a particular endpoint is enabled or disabled.
Each endpoint has one bit assigned in the EP DMA Status register. Bit 0 corresponds to
endpoint 0 and Bit 31 to endpoint 15 IN). DMA transfer for a specific endpoint can start
only if its bit is set in the USBEpDMASt register. Hence, it is referred as DMA_ENABLE
bit. If the bit in the EP DMA Status register is made 0 (by writing into EP DMA Disable
register) in between a packet transfer, the current packet transfer will still be completed.
After the current packet, DMA gets disabled. In other words, the packet transfer when
started will end unless an error condition occurs. When error condition is detected the bit
will be reset by the hardware. The USBEpDMASt is a read only register.
Table 211: USB EP DMA Status register (USBEpDMASt - address 0xE009 0084) bit
Bit
0
1
31:2 EPxx_DMA_ENABLE
Software does not have direct write permission to this register. It has to set the bit through
EP DMA Enable register. Resetting of the bit is done through EP DMA Disable register.

14.8.16 USB EP DMA Enable register (USBEpDMAEn - 0xE009 0088)

Writing 1 to this register will enable the DMA operation for the corresponding endpoint.
Writing 0 will not have any effect. The USBEpDMAEn is a write only register.
Table 212: USB EP DMA Enable register (USBEpDMAEn - address 0xE009 0088) bit
Bit
0
1
31:2 EPxx_DMA_ENABLE

14.8.17 USB EP DMA Disable register (USBEpDMADis - 0xE009 008C)

Writing 1 to this register will disable the DMA operation for the corresponding endpoint.
Writing 0 will have the effect of resetting the DMA_PROCEED flag. The USBEpDMADis is
a write only register.
9397 750 XXXXX
User manual
description
Symbol Value Description
EP0_DMA_ENABLE 0
EP1_DMA_ENABLE 0
0
1
description
Symbol Value Description
EP0_DMA_ENABLE 0
EP1_DMA_ENABLE 0
0
1
Rev. 01 — 15 August 2005
Chapter 14: USB Device Controller
Control endpoint OUT (DMA cannot be enabled for
this endpoint and the EP0_DMA_ENABLE bit must
be 0).
Control endpoint IN (DMA cannot be enabled for this
endpoint and the EP1_DMA_ENABLE bit must be
0).
≤ ≤
endpoint xx (2 xx 31) DMA enabled bit.
The DMA for endpoint EPxx is disabled.
The DMA for endpoint EPxx is enabled.
Control endpoint OUT (DMA cannot be enabled for
this endpoint and the EP0_DMA_ENABLE bit value
must be 0).
Control endpoint IN (DMA cannot be enabled for this
endpoint and the EP1_DMA_ENABLE bit must be 0).
≤ ≤
Endpoint xx (2 xx 31) DMA enable control bit.
No effect.
Enable the DMA operation for endpoint EPxx.
UM10139
© Koninklijke Philips Electronics N.V. 2005. All rights reserved.
Reset
value
0
0
0
Reset
value
0
0
0
217