ALXD800EEXJ2VD AMD (ADVANCED MICRO DEVICES), ALXD800EEXJ2VD Datasheet - Page 528

• Manufacturer Part Number: ALXD800EEXJ2VD
• Manufacturer: AMD (ADVANCED MICRO DEVICES)

Specifications of ALXD800EEXJ2VD

• Operating Temperature (min): 0C
• Operating Temperature (max): 85C
• Operating Temperature Classification: Commercial
• Mounting: Surface Mount
• Lead Free Status / RoHS Status: Compliant

6.12.3.23 SB EEPROM Security State (SB_EEPROM_SEC_STATE)
SB Memory Offset 80Ch
Type
Reset Value
This read only register contains the current state of the access control bits for controlling reads and writes from/to the
EEPROM. It is reloaded from the EEPROM array after every reset. The initial state of the EEPROM is all ones. Therefore
the unlocked state of the control bits must be one. The user locks the part by programming zeroes into the protect bits of
the Access Control bytes. Each lock control is a 3-bit field. The user normally programs all three bits to a zero. The multi-bit
fields are used to prevent a single bit disturb of the EEPROM array from unlocking the part.
528
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10
31:14
13:11
10:8
Bit
7:6
5:3
2:0
WPE
Name
RSVD
DBL
RSVD
WPU
WPL
RO
00000000h
33234C
RSVD
Description
Reserved.
Write Protect Extended. Reserved for future use. This register holds the 3-bit value of
the access control bits used to block write access to any address above the 2 kbit range
(byte address greater than 255). This is included for possible future support of larger
EEPROM memories. With the currently specified 2 kbit memory, these bits have no
effect. If any of these bits are reset, write operations are blocked to addresses above
255. These bits correspond to the state of bits 5:3 of byte 1of the EEPROM array as
read after the last reset. To change these bits, the user must program the Access Con-
trol byte 1 (address 1 of the EEPROM), and the part must be reset.
Debug Lock. This register holds the 3-bit value of the access control bits used to dis-
able certain debug features of the Geode™ LX processor. If any of these bits are reset,
debug operations are blocked. These bits correspond to the state of bits [2:0] of byte 1
of the EEPROM array as read after the last reset. To change these bits, the User must
program the Access Control byte 1 (address 1 of the EEPROM), and the part must be
reset. Although reset to the locked state (000), these bits will revert to the unlocked state
(111), if no EEPROM is detected after reset. This unlocking will occur approximately 17
ms after the release from reset with no EEPROM present.
Reserved.
Write Protect Upper. This register holds the 3-bit value of the access control bits used
to block write access to the upper half of the EEPROM array, (address 120 through
255). If any of these bits are reset, write operations are blocked. These bits correspond
to the state of bits [5:3] of byte 0 of the EEPROM array as read after the last reset. To
change these bits, the user must program the Access Control byte 0 (address 0 of the
EEPROM), and the part must be reset.
Write Protect Lower. This register holds the 3-bit value of the access control bits used
to block write access to the lower half of the EEPROM array, (address 0 through 127).
(Note, these addresses include these access control bits as well as the hidden key bits.)
If any of these bits are reset, write operations are blocked forever. These bits correspond
to the state of bits [2:0] of byte 0 of the EEPROM array as read after the last reset. To
change these bits, the user must program the Access Control byte 0 (address 0 of the
EEPROM), and the part must be reset.
SB_EEPROM_SEC_STATE Bit Descriptions
SB_EEPROM_SEC_STATE Register Map
EEPROM byte 1
WPE
AMD Geode™ LX Processors Data Book
DBL
9
Security Block Register Descriptions
8
RSVD
7
6
EEPROM byte 0
5
WPU
4
3
2
WPL
1
0