DP83907 datasheet(9/70 Pages) NSC

9 / 70 page

30 Simplified Application Diagram (Continued)

TLF12082 – 4

FIGURE 1 Block Diagram of DP83907

40 Functional Description

The DP83907 is a highly integrated and configurable Ether-

net controller making it suitable for most Ethernet applica-

tions The DP83907 integrates the functions of the following

blocks

1 ISA Bus Interface containing all logic required to connect

the DP8390 core to a packet buffer RAM and the ISA

bus

2 DP8390 Ethernet Controller Core and Media Access

Control logic

3 Media Interface which includes a TPI transceiver

41 BUS INTERFACE BLOCK

The DP83907’s Bus interface block provides the circuitry to

interface the Ethernet controller logic and the external pack-

et buffer RAM to an ISA (Industry Standard Architecture)

Bus The bus interface provides an NE2000 Architecture

compatible IO port architecture supporting both 8-bit and

16-bit wide ISA Bus slots

DETERMINING 8-BIT OR 16-BIT WIDE DATA

DP83907 can treat the system data bus and all internal data

busses as 8 bits or 16 bits wide 8-bit or 16-bit mode is

determined by MSA9 at reset For an adapter card this pin

can be used to automatically detect if the card has been

plugged into an 8-bit or 16-bit slot by connecting MSA9 via a

10 kX pull-up resistor to a VDD on the upper connector It

will be pulled high when plugged into a 16-bit slot enabling

16-bit mode and floating when plugged into an 8-bit slot

When floating the internal pull-down resistor will enable 8-bit

mode

DP83907 датащи(PDF) 9 Page - National Semiconductor (TI)