Data Sheet

Ethernet Controller I210 — Programming Interface
390
This register provides software direct access to the EEPROM. Software can control the EEPROM by
successive writes to this register. Data and address information is clocked into the EEPROM by software
toggling the EE_SK and EE_DI bits (0 and 2) of this register with EE_CS set to 0b. Data output from the
EEPROM is latched into the EE_DO bit (bit 3) via the internal 62.5 MHz clock and can be accessed by
software via reads of this register.
Bit banging access to the flash via the FLA register is not protected by this field.
Reserved 31:28 0x0 Reserved. Reads as 0b.
Field Bit(s) Initial Value Description
EE_SK 0 0b
Clock input to the EEPROM
When EE_GNT = 1b, the EE_SK output signal is mapped to this bit and provides
the serial clock input to the EEPROM. Software clocks the EEPROM via toggling
this bit with successive writes.
EE_CS 1 1b
Chip select input to the EEPROM
When EE_GNT = 1b, the EE_CS output signal is mapped to the chip select of the
EEPROM device. Software enables the EEPROM by writing a 0b to this bit.
EE_DI 2 1b
Data input to the EEPROM
When EE_GNT = 1b, the EE_DI output signal is mapped directly to this bit.
Software provides data input to the EEPROM via writes to this bit.
EE_DO (RO) 3 X
1
Data output bit from the EEPROM
The EE_DO input signal is mapped directly to this bit in the register and contains
the EEPROM data output. This bit is RO from a software perspective; writes to
this bit have no effect.
FWE 5:4 01b
Flash Write Enable Control
These two bits, control whether writes to Flash memory are allowed.
00b = Flash erase (along with bit 31 in the FLA register).
01b = Flash writes disabled.
10b = Flash writes enabled.
11b = Reserved.
EE_REQ 6 0b
Request EEPROM Access
The software must write a 1b to this bit to get direct EEPROM access. It has
access when EE_GNT is 1b. When the software completes the access it must
write a 0b.
EE_GNT 7 0b
Grant EEPROM Access
When this bit is 1b the software can access the EEPROM using the SK, CS, DI,
and DO bits.
EE_PRES (RO) 8 X
EEPROM Present and Signature is valid
This bit indicates that an EEPROM is present and the value of the Signature field
in the EEPROM Sizing and Protected Fields EEPROM word (Word 0x12) is 01b
0b = Signature field invalid
1b = EEPROM present and signature is valid.
Auto_RD (RO) 9 0b
EEPROM Auto Read Done
When set to 1b, this bit indicates that the auto read by hardware from the
EEPROM is done. This bit is also set when the EEPROM is not present or when its
signature is not valid.
EE_ADDR_SIZE
(RO)
10 1b
EEPROM Address Size
This field defines the address size of the EEPROM.
This bit is set by the EEPROM size auto-detect mechanism. If no EEPROM is
present or the signature is not valid, a 16-bit address is assumed.
0b = 8- and 9-bit.
1b = 16-bit.
Field Bit(s) Init. Description