DP83916 datasheet(10/96 Pages) NSC

10 / 96 page

10 Functional Description (Continued)

4 Program the Receive Control register with the desired re-

ceive filter and the loopback mode (LB1 LB0)

5 Issue the transmit command (TXP) and enable the receiv-

er (RXEN) in the Command register

The SONIC-16 completes the loopback operation after the

packet has been completely received (or rejected if there is

an address mismatch) The Transmit Control and Receive

Control registers treat the loopback packet as in normal op-

eration and indicate status accordingly Interrupts are also

generated if enabled in the Interrupt Mask register

Note

For MAC Loopback only one packet may be queued for proper oper-

ation This restriction occurs because the transmit MAC section

which does not generate an Interframe Gap time (IFG) between

transmitted packets does not allow the receive MAC section to up-

date receive status There are no restrictions for the other loopback

modes

18 NETWORK MANAGEMENT FUNCTIONS

The SONIC-16 fully supports the Layer Management IEEE

8023 standard to allow a node to monitor the overall per-

formance of the network These statistics are available on a

per packet basis at the end of reception or transmission In

addition the SONIC-16 provides three tally counters to tab-

ulate CRC errors Frame Alignment errors and missed

packets Table 1-1 shows the statistics indicated by the

SONIC-16

TLF11722 – 8

Note DSACK01 are used for both Bus and Slave Access Control and are bidirectional SMACK is used for both Slave access and shared memory access The

BMODE pin selects between NationalIntel or Motorola type buses

FIGURE 1-7 SONIC-16 Interface Signals

DP83916 Datasheet(PDF) 10 Page - National Semiconductor (TI)