DP83932C NSC [National Semiconductor], DP83932C Datasheet - Page 32

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

10 9
Bits
4 0 SONIC Registers
4 3 3 Receive Control Register (Continued)
8
7
6
5
4
3
2
1
0
LB1 LB0 LOOPBACK CONTROL
These encoded bits control loopback operations for MAC loopback ENDEC loopback and Transceiver loopback For
proper loopback operation the CAM Address registers and Receive Control register must be initialized to accept the
Destination address of the loopback packet (see Section 1 7)
Note A hardware reset clears these bits
LB1
MC MULTICAST PACKET RECEIVED
This bit is set when a packet is received with a Multicast Address
BC BROADCAST PACKET RECEIVED
This bit is set when a packet is received with a Broadcast Address
LPKT LAST PACKET IN RBA
This bit is set when the last packet is buffered into a Receive Buffer Area (RBA) The SONIC detects this condition
when its Remaining Buffer Word Count (RBWC0 1) register is less than or equal to the End Of Buffer Count (EOBC)
register (See Section 3 4 2 )
CRS CARRIER SENSE ACTIVITY
Set when CRS is active Indicates the presence of network activity
COL COLLISION ACTIVITY
Indicates that the packet received had a collision occur during reception
CRCR CRC ERROR
Indicates the packet contains a CRC error If the packet also contains a Frame Alignment error FAER will be set
instead (see bit 2 below) The rev C SONIC has the potential to report CRC error’d frames as FAE This bit is also not
set during CRC error’d RUNT packets
FAER FRAME ALIGNMENT ERROR
Indicates that the incoming packet was not correctly framed on an 8-bit boundary Note if no CRC errors have
occurred this bit is not set (i e this bit is only set when both a frame alignment and CRC error occurs)
LBK LOOPBACK PACKET RECEIVED
Indicates that the SONIC has successfully received a loopback packet
PRX PACKET RECEIVED OK
Indicates that a packet has been received without CRC frame alignment length (runt packet) errors or collisions
0
0
1
1
LB0
0
1
0
1
no loopback normal operation
MAC loopback
ENDEC loopback
Transceiver loopback
(Continued)
Function
Description
32