DM9081F datasheet(8/22 Pages) ETC

номер детали	DM9081F

подробное описание детали	10BASE-T Hub Controller

PDF	22 Pages

Scroll/Zoom	100%

производитель	ETC [List of Unclassifed Manufacturers]

домашняя страница

Logo

8 / 22 page

DM9081

Final

Version: DM9081-DS-F01

April 22, 1997

External Logic

A simple logic scheme is required when more than two

DM9081 chips are connected to increase the total number

of repeater ports. The external logic should have one input

(EXPOUT#) and one output (EXPIN#) for each DM9081

chip. This function is easily implemented in a PAL device,

using the following logical equations:

EXPIN1# =

EXPOUT2# &

EXPOUT3# &

….. EXPOUTn#

EXPIN2# =

EXPOUT1# &

EXPOUT3# &

….. EXPOUTn#

EXPIN3# =

EXPOUT1# &

EXPOUT2# &

….. EXPOUTn#

EXPINn# =

EXPOUT1# &

EXPOUT2# &

….. EXPOUTN-1#

The above equations are in positive logic, i.e., a variable is

true when asserted. An example of three banked DM9081

chips is shown in Figure 1. The cascade IC number

recommended: under 3 and inclusive.

Note that if the design includes only two DM9081 chips,

then EXPOUT1# is connected to EXPIN2#, EXPOUT2# is

connected to EXPIN1#, and no external logic is required.

A single PAL16L8 performs the arbitration function for a

repeater based on several DM9081 chips.

Figure 1. Multiple DM9081 Devices

DM9081F датащи(PDF) 8 Page - List of Unclassifed Manufacturers