adm6996f Infineon Technologies Corporation, adm6996f Datasheet - Page 46

• Manufacturer Part Number: adm6996f
• Description: 6 Port 10/100 Mb/s Single Chip Ethernet Switch Controller
• Manufacturer: Infineon Technologies Corporation

ADM6996F
Infineon-ADMtek Co Ltd
ADM6996F serial chips will latch hardware-reset value as recommend value. It includes
EEPROM interface:
EECS: Internal Pull down 40K resistor.
EESK: TP port Auto-MDIX select. Internal pull down 40K resistor as non Auto-MDIX
mode.
EDI: Dual Color Select. Internal pull down 40K resistor as Single Color Mode.
EDO: EEPROM enable. Internal pull up 40K resistor as EEPROM enable.
Below Figure is ADM6996F serial chips EEPROM pins operation at different stage.
Reset signal is control by CPU with at least 100ms low. Point1 is Reset rising edge. CPU
must prepare proper value on EECS(0), EESK, EDI, EDO(1) before this rising edge.
ADM6996F will read this value into chip at Point2. CPU must keep these values over
point2. Point2 is 200ns after Reset rising edge.
ADM6996F serial chips will read EEPROM content at Point4 which 800ns far away
from the rising edge of Reset. CPU must turn EEPROM pins EECS, EESK, EDI and
EDO to High-Z or pull high before Point4.
If user want change state to High-Z or pull high on EEPROM pins, the order is CS-> DI -
> DO -> SK is better.
It’s a little different with the timing on the writing EEPROM. See below graph. One must
be carefull when CS goes down after write a command, SK must issue at least one clock.
This is a difference between the ADM6996F with EEPROM write timing. If the system is
without EEPROM then user must write ADM6996F internal register by 93C66 timing. If
user uses EEPROM then the writing timing is dependent on EEPROM type.
Reset
SK
CS
100mS
1
200nS
Write Command
2
800nS
3
4
200nS
Register Description
5
4-5