XMC-6VLX
USER’S MANUAL
Acromag, Inc. Tel: 248-295-0310
- 25 - http://www.acromag.com
- 25 -
www.acromag.com
1
Error Interrupt Enabled
15
Reserved
23-16
Interrupt Threshold value. This field is used to set the Scatter
Gather interrupt coalescing threshold. When Interrupt On
Complete interrupt events occur, an internal counter counts
down from the Interrupt Threshold setting. When the count
reaches zero, an interrupt out is generated by the CDMA
engine.
Note:
The minimum setting for the threshold is 0x01. A write
of 0x00 to this register has no effect. If the CDMA is built with
Scatter Gather disabled (Simple Mode Only), the default value
of the port is zeros.
31-24
Interrupt Delay Time Out. This value is used for setting the
interrupt delay time out value. The interrupt time out is a
mechanism for causing the CDMA engine to generate an
interrupt after the delay time period has expired. This is used
for cases when the interrupt threshold is not met after a
period of time, and the CPU desires an interrupt to be
generated. Timer begins counting when the CDMA is IDLE
(CDMA Status bit-1 = ‘1’). This generally occurs when the
CDMA has completed all scheduled work defined by the
transfer descriptor chain (reached the tail pointer) and has not
satisfied the Interrupt Threshold count.
Note:
Setting this value to zero disables the delay timer
interrupt.
