Transmit buffer descriptor pointer offset register, Register bit assignment – Digi NS9750 User Manual
Page 418
E t h e r n e t C o n t r o l a n d S t a t u s r e g i s t e r s
3 9 4
N S 9 7 5 0 H a r d w a r e R e f e r e n c e
Register bit assignment
Transmit Buffer Descriptor Pointer Offset register
Address: A060 0A38
Register bit assignment
Bits
Access
Mnemonic
Reset
Description
D31:11
N/A
Reserved
N/A
N/A
D10:00
R
RXDOFF
0x000
Contains an 11-bit byte offset from the start of the pool D
ring. The offset is updated at the end of the RX packet, and
will have the offset to the next buffer descriptor that will
be used. RXDOFF can be used to determine where the
RX_RD
logic will put the next packet.
Table 248: RX_D Buffer Descriptor Pointer Offset register
Bits
Access
Mnemonic
Reset
Description
D31:10
N/A
Reserved
N/A
N/A
D09:00
R
TXOFF
0x000
Contains a 10-bit byte offset from the start of the transmit
ring in the TX buffer descriptor RAM. The offset is
updated at the end of the TX packet, and will have the
offset to the next buffer descriptor that will be used.
TXOFF can be used to determine from where the
TX_WR
logic will grab the next packet.
Table 249: TX Buffer Descriptor Pointer Offset register
Reserved
TXOFF
13
12
11
10
9
8
7
6
5
4
3
2
1
0
15
14
31
29
28
27
26
25
24
23
22
21
20
19
18
17
16
30
Reserved