Altera cyclone V Technical Reference page 1245

17-30
Transmit Descriptor
Figure 17-10: Transmit Enhanced Descriptor Fields - Format
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10
O
TDES0 W Ctrl [30:26]
N
TDES1
RES
T E D 2 S
T E D 3 S
T E D 4 S
T E D 5 S
T E D 6 S
T E D 7 S
The DMA always reads or fetches four DWORDS of the descriptor from system memory to obtain the
buffer and control information.
Altera Corporation
T
T
Ctrl [24:18]
S
E
Buffer 2 Byte Count [28:16]
u B r e f f A 2 r d d s s e
T n a r
T n a r
†
T
T
Status [16:7]
S
S
RES
u B r e f f A 1 r d d s s e 1 3 [ ] 0 :
3 [ 0 : 1 o ] N r x e D t s e i r c o t p A r r d d
R s e v r e d e
R s e v r e d e
m s T t i m i t s e m a L p w o 1 3 [ ] 0 :
m s T t i m i t s e m a H p h g i 1 3 [ ] 0 :
9 8 7 6 5 4
Ctrl/Status
[6:3]
Buffer 1 Byte Count [12:0]
s s e 1 3 [ ] 0 :
Ethernet Media Access Controller
Send Feedback
cv_5v4
2016.10.28
3 2 1 0
Status
[2:0]