XMC-6VLX
USER’S MANUAL
Acromag, Inc. Tel: 248-295-0310
- 24 - http://www.acromag.com
- 24 -
www.acromag.com
CDMA Control Register (Read/Write) - (BAR0 + 0x000A0000)
This register provides software application control of the AXI CDMA.
Table 3.9:
CDMA Control
Register
Bit(s)
FUNCTION
0
This bit is reserved for future definition and will always return
zero.
1
Indicates tail pointer mode is enabled to the Scatter Gather
Engine. This bit is fixed to 1 and always read as 1 when
Scatter Gather is included. If the CDMA is built with Scatter
Gather disabled (Simple Mode Only), the default value of the
port is 0.
0
Tail Pointer Mode is Disabled
1
Tail Pointer Mode is Enabled
2
Soft reset control for the AXI CDMA core. Setting this bit to a
‘1’ causes the AXI CDMA to be reset. Reset is accomplished
gracefully. Committed AXI4 transfers are then completed.
Other queued transfers are flushed. After completion of a
soft reset, all registers and bits are in the Reset State.
0
Reset Not in Progress
1
Reset in Progress
3
This bit controls the transfer mode of the CDMA. Setting this
bit to a ‘1’ causes the AXI CDMA to operate in a Scatter Gather
mode.
Note:
This bit must only be changed when the CDMA engine is
IDLE (CDMA Status bit-1 = ‘1’). Changing the state of this bit
at any other time has undefined results.
Note:
This bit must be set to a 0 then back to 1 by the
software application to force the CDMA Scatter Gather engine
to use a new value written to the CDMA Current Descriptor
Pointer register.
Note:
This bit must be set prior to setting Bit-13 of this CDMA
Control register.
0
Simple DMA Mode
1
Scatter Gather Mode
11-4
Reserved
12
Interrupt on Complete Interrupt Enable. When set to ‘1’, it
allows an interrupt after completed DMA transfers.
0
Interrupt on Complete Disabled
1
Interrupt on Complete Enabled
13
Interrupt on Delay Timer Interrupt Enable. When set to ‘1’, it
allows a delayed interrupt out. This is only used with Scatter
Gather assisted transfers.
0
Delayed Interrupt Disabled
1
Delayed Interrupt Enabled
14
Interrupt on Error Interrupt Enable. When set to ‘1’, it allows
an error to generate an interrupt out.
0
Error Interrupt Disabled