32-Bit Resultant CRC
26
Received Message
Destination Address
1
31
0
47
0
1
CRC
GEN
Logical
Address Filter
(LADRF)
63
0
SEL
64
Match
MUX
Match = 1 Packet Accepted
Match = 0 Packet Rejected
6
22206B-54
Figure 51. Address Match Logic
receive descriptors look like Table 83 (CRDA = Current
Receive Descriptor Address).
Receive Descriptors
When SWSTYLE (BCR20, bits 7-0) is set to 0, then the
software structures are defined to be 16 bits wide, and
receive descriptors look like Table 82 (CRDA = Current
Receive Descriptor Address).
When SWSTYLE (BCR 20, bits 7-0) is set to 3, then the
software structures are defined to be 32 bits wide, and
receive descriptors look like Table 84 (CRDA = Current
Receive Descriptor Address).
When SWSTYLE (BCR 20, bits 7-0) is set to 2, then the
software structures are defined to be 32 bits wide, and
Table 82. Receive Descriptor (SWSTYLE = 0)
Address
CRDA+00h
CRDA+02h
CRDA+04h
CRDA+06h
15
14
13
12
11
RBADR[15:0]
CRC BUFF
10
9
8
7-0
OWN
ERR
FRAM
OFLO
STP
ENP
RBADR[23:16]
1
0
1
0
1
0
1
0
BCNT
MCNT
Table 83. Receive Descriptor (SWSTYLE = 2)
Address
31
30
29
28
27
26
25
24
23
22
21
20
19-16 15-12
11-0
CRDA+00h
RBADR[31:0]
FRA OFL
BUF
F
CRDA+04h OWN ERR
CRC
STP ENP BPE PAM LAFM BAM
RES
1111 BCNT
0000 MCNT
M
O
CRDA+08h RES
CRDA+0Ch
RFRTAG[14:0]
USER SPACE
Table 84. Receive Descriptor (SWSTYLE = 3)
Address
31
30
29
28
27
26
25
24
23
22-16
RES
RES
15-12
11-0
CRDA+00h
RES
ERR FRAM OFLO CRC
RES
BPE
0000
1111
MCNT
BCNT
CRDA+04h OWN
CRDA+08h
BUFF
STP
ENP
RBADR[31:0]
USER SPACE
CRDA+0Ch
200
Am79C978
AMD [ AMD ]
