DP83932C NSC [National Semiconductor], DP83932C Datasheet - Page 31

• Manufacturer Part Number: DP83932C
• Description: MHz SONICTM Systems-Oriented Network Interface Controller
• Manufacturer: NSC [National Semiconductor]

4 0 SONIC Registers
4 3 3 Receive Control Register
(RA
This register is used to filter incoming packets and provide status information of accepted packets (Figure 4-6) Setting any of
bits 15 –11 to a ‘‘1’’ enables the corresponding receive filter If none of these bits are set only packets which match the CAM
Address registers are accepted Bits 10 and 9 control the loopback operations
After reception bits 8–0 indicate status information about the accepted packet and are set to ‘‘1’’ when the corresponding
condition is true If the packet is accepted all bits in the RCR are written into the RXpkt status field Bits 8– 6 and 3– 0 are
cleared at the reception of the next packet
This register is unaffected by a software reset
k
r
e
ERR
Bit
r w
15
14
13
12
11
5 0
15
read only r w
l
e
RNT
r w
14
2h)
e
read write
BRD
r w
13
ERR ACCEPT PACKET WITH CRC ERRORS OR COLLISIONS
0 Reject all packets with CRC errors or when a collision occurs
1 Accept packets with CRC errors and ignore collisions
RNT ACCEPT RUNT PACKETS
0 Normal address match mode
1 Accept runt packets (packets less than 64 bytes in length)
Note A hardware reset clears this bit
BRD ACCEPT BROADCAST PACKETS
0 Normal address match mode
1 Accept broadcast packets (packets with addresses that match the CAM are also accepted)
Note This bit is cleared upon hardware reset
PRO PHYSICAL PROMISCUOUS MODE
Enable all Physical Address packets to be accepted
0 normal address match mode
1 promiscuous mode
AMC ACCEPT ALL MULTICAST PACKETS
0 normal address match mode
1 enables all multicast packets to be accepted Broadcast packets are also accepted regardless
PRO
of the BRD bit (Broadcast packets are a subset of multicast packets )
r w
12
(Continued)
AMC
r w
11
ERR
RNT
BRD
PRO
AMC
LB0 LB1
MC
BC
LPKT
CRS
COL
CRCR
FAER
LBK
PRX
Field
LB1
r w
FIGURE 4-6 Receive Control Register
10
LB0
r w
9
ACCEPT PACKET WITH ERRORS
ACCEPT RUNT PACKETS
ACCEPT BROADCAST PACKETS
PHYSICAL PROMISCUOUS PACKETS
ACCEPT ALL MULTICAST PACKETS
LOOPBACK CONTROL
MULTICAST PACKET RECEIVED
BROADCAST PACKET RECEIVED
LAST PACKET IN RBA
CARRIER SENSE ACTIVITY
COLLISION ACTIVITY
CRC ERROR
FRAME ALIGNMENT ERROR
LOOPBACK PACKET RECEIVED
PACKET RECEIVED OK
MC
8
r
31
BC
7
Meaning
r
Description
LPKT
6
r
CRS
5
r
COL CRCR FAER
4
r
3
r
2
r
LBK
1
r
PRX
0
r