DP83936AVF NSC [National Semiconductor], DP83936AVF Datasheet - Page 73

• Manufacturer Part Number: DP83936AVF
• Description: Full Duplex SONICTM-T Systems-Oriented Network Interface Controller with Twisted Pair Interface
• Manufacturer: NSC [National Semiconductor]

7 0 Bus Interface
A software reset immediately terminates DMA operations
and future interrupts The chip is put into an idle state where
registers can be accessed but the SONIC-T will not be ac-
tive in any other way The registers are affected by a soft-
ware reset as shown in Table 7-3 (only the Command Reg-
ister is changed)
8 0 Network Interfacing
The SONIC-T contains an on-chip ENDEC that performs the
network interfacing between the AUI (Attachment Unit Inter-
face) and the SONIC-T’s MAC unit A pin selectable option
(Continued)
FIGURE 8-1 MAC and Internal ENDEC Interface Signals
73
allows the internal ENDEC to be disabled and the
MAC ENDEC signals to be supplied to the user for connec-
tion to an external ENDEC If the EXT pin is tied to ground
(EXT
to V
Internal ENDEC
(EXT
MAC unit are internally connected While these signals are
used internally by the SONIC-T they are also provided as an
output to the user (Figure 8-1)
The internal ENDEC allows for a 2-chip solution for the
complete Ethernet interface Figure 8-2 shows a typical dia-
gram of the Thin Ethernet and AUI network interface
CC
e
e
0) the internal ENDEC is selected and if EXT is tied
0) the interface signals between the ENDEC and
(EXT
e
1) the external ENDEC option is selected
When the internal ENDEC is used
TL F 12597 – 51
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