adm6999ux Infineon Technologies Corporation, adm6999ux Datasheet - Page 59

• Manufacturer Part Number: adm6999ux
• Description: Adm6999u 9 Port 10/100 Mb/s Single Chip Ethernet Switch Controller
• Manufacturer: Infineon Technologies Corporation

3.6
Customer can select ADM6999U/UX read EEPROM contents as chip setting or not. ADM6999U/UX will check the
signature of EEPROM to decide read content of EEPROM or not.
Table 18
RC
0
Rising edge 01
(30ms)
1 (after 30 ms)
Keep at least 30 ms after RC from 0 to 1. ADM6999U/UX will read data from EEPROM. After RC if CPU update
EEPROM that ADM6999U/UX will update configuration registers too.
When CPU programs EEPROM & ADM6999U/UX, ADM6999U/UX recognizes the EEPROM WRITE instruction
only. If there is any Protection instruction before or after the EEPROM WRITE instruction, CPU needs to generate
separated CS signal cycle for each Protection & WRITE instruction.
CPU can directly program ADM6999U/UX after 30ms of Reset signal rising edge with or without EEPROM.
ADM6999U/UX serial chips will latch hardware-reset value as recommend value. It includes EEPROM interface:
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•
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Below Figure is ADM6999U/UX 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 ECS(0), EESK, EDI,
EDO(1) before this rising edge. ADM6999U/UX will read this value into chip at Point2. CPU must keep these
values over point2. Point2 is 200ns after Reset rising edge.
ADM6999U/UX 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 users want change the state to High-Z or pull high on EEPROM pins, the order is CS-> DI -> DO -> SK is better.
Figure 8
Data Sheet
EECS: Internal Pull down 40K resister.
EESK: TP port Auto-MDIX select. Internal pull down 40K resister as non Auto-MDIX mode.
EDI: Dual Color Select. Internal pull down 40K resister as Single Color Mode.
EDO: EEPROM enable. Internal pull up 40K resister as EEPROM enable.
Reset
EEPROM Access Description
RC & EEPROM Content Relationship
ADM6999U/UX serial chips EEPROM pins operation
CS
High Impedance
Output
Input
100mS
SK
High Impedance
Output
Input
1
200nS
59
2
800nS
DI
High Impedance
Output
I/O
3
4
Rev. 1.42, 2005-11-25
DO
High Impedance
Input
Input
200nS
ADM6999U/UX
Data Sheet
Descriptions
5