![Acromag XMC-6VLX Series Скачать руководство пользователя страница 32](http://html1.mh-extra.com/html/acromag/xmc-6vlx-series/xmc-6vlx-series_user-manual_2841192032.webp)
XMC-6VLX
USER’S MANUAL
Acromag, Inc. Tel: 248-295-0310
- 30 - http://www.acromag.com
- 30 -
www.acromag.com
CDMA Tail Descriptor Pointer Register (Read/Write) - (BAR0 + 0x000A0010)
This register provides Tail Descriptor Pointer for the AXI CDMA Scatter
Gather Descriptor Management.
Table 3.12:
CDMA Tail
Descriptor Pointer Register
Bit(s)
FUNCTION
5-0
Writing to these bits has no effect and they are always read
as zeros.
31-6
Tail Descriptor Pointer. This register field is written by the
software application (in Scatter Gather Mode) to set the
current pause pointer for descriptor chain execution. The AXI
CDMA Scatter Gather Engine pauses descriptor fetching after
completing operations on the descriptor whose current
descriptor pointer matches the tail descriptor pointer. When
the AXI CDMA is in Scatter Gather Mode, a write by the
software application to this register causes the AXI CDMA
Scatter Gather Engine to start fetching descriptors starting
from the Current Descriptor Pointer register value. If the
Scatter Gather engine is paused at a tail pointer pause point,
the Scatter Gather engine restarts descriptor execution at the
next sequential transfer descriptor. If the AXI CDMA is not
idle, writing to this register has no effect except to reposition
the Scatter Gather pause point.
Note:
The software application must not move the tail pointer
to a location that has not been updated with valid transfer
descriptors. The software application must process and
reallocate all completed descriptors, clear the completed bits
and then move the tail pointer. The software application
must move the pointer to the last descriptor address it has
updated.
Содержание XMC-6VLX Series
Страница 72: ...XMC 6VLX USER S MANUAL Acromag Inc Tel 248 295 0310 70 http www acromag com 70 www acromag com...
Страница 77: ...XMC 6VLX USER S MANUAL Acromag Inc Tel 248 295 0310 75 http www acromag com 75 www acromag com...
Страница 109: ...XMC 6VLX USER S MANUAL Acromag Inc Tel 248 295 0310 107 http www acromag com 107 www acromag com...