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Texas Instruments THUNDER TNETX3270 User Manual

Page 60

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TNETX3270
ThunderSWITCH

24/3 ETHERNET

SWITCH

WITH 24 10-MBIT/S PORTS AND 3 10-/100-MBIT/S PORTS

SPWS043B – NOVEMBER 1997 – REVISED APRIL 1999

60

POST OFFICE BOX 655303

DALLAS, TEXAS 75265

serial MII management interface

timing requirements (see Figure 20)

NO.

MIN

MAX

UNIT

1

tsu(MDIO)

Setup time, MDIO valid before OSCIN

, read

7

ns

2

th(MDIO)

Hold time, MDIO valid after OSCIN

, read

3

ns

operating characteristics over recommended operating conditions (see Figure 20)

NO.

PARAMETER

MIN

MAX

UNIT

3

td(MDIO)

Delay time, from OSCIN

to MDIO valid, write

11

ns

4

td(MDCLK)

Delay time, from OSCIN

to MDCLK

11

ns

5

td(MRESET)

Delay time, from OSCIN

to MRESET

11

ns

6

tdis(MDIO)

Disable time, from OSCIN

to after MDIO to Z state, read

11

ns

7

tdis(MDCLK)

Disable time, from OSCIN

to after MDCLK to Z state

11

ns

8

tdis(MRESET) Disable time, from OSCIN

to after MRESET to Z state

11

ns

9

ten(MDIO)

Enable time, from OSCIN

to before MDIO valid

11

ns

10

ten(MDCLK)

Enable time, from OSCIN

to before MDCLK valid

11

ns

11

ten(MRESET)

Enable time, from OSCIN

to before MRESET valid

11

ns

OSCIN

(input)

MDCLK

(output)

MRESET

(output)

MDIO

(input/

output)

1

6

9

2

3

7

10

8

4

5

Z

Z

Z

Read Input

Write Output

11

Figure 20. Serial MII Management Read/Write Cycle