R
Platform Flash XL High-Density Configuration and Storage Device
•
•
The first cycle sets up the Set Configuration Register
command and the address corresponding to the
Configuration Register content.
Block Unlock Command
The Block Unlock command is used to unlock a block,
allowing the block to be programmed or erased.
The second cycle writes the Configuration Register
data and the confirm command.
Two Bus Write cycles are required to issue the Block Unlock
command:
The Configuration Register data must be written as an
address during the bus write cycles, that is A0 = CR0,
A1 = CR1, …, A15 = CR15. Addresses A16–A22 are
ignored. Read operations output the array content after the
Set Configuration Register command is issued.
•
•
The first bus cycle sets up the Block Unlock command.
The second Bus Write cycle latches the block address
and unlocks the block.
The lock status can be monitored for each block using the
Read Electronic Signature command. Table 18, page 38
shows the protection status after issuing a Block Unlock
command.
The Read Electronic Signature command is required to
read the updated contents of the Configuration Register.
Block Lock Command
Refer to the "Block Locking," page 37 for a detailed
explanation and Figure 43, page 77, for a flowchart for
using the Block Unlock command.
The Block Lock command is used to lock a block and
prevent program or erase operations from changing the
contents. All blocks are locked after power-up or reset.
Block Lock-Down Command
Two Bus Write cycles are required to issue the Block
Lock command:
The Block Lock-Down command is used to lock down a
locked or unlocked block.
•
•
The first bus cycle sets up the Block Lock command.
A locked-down block cannot be programmed or erased. The
lock status of a locked-down block cannot be changed when
The second Bus Write cycle latches the block address
and locks the block.
WP is Low (at V ). When WP is High (at V ), the Lock-
Down function is disabled, and the locked blocks can be
individually unlocked by the Block Unlock command.
IL
IH
The lock status can be monitored for each block using the
Read Electronic Signature command. Table 18, page 38
shows the Lock Status after issuing a Block Lock command.
Two Bus Write cycles are required to issue the Block Lock-
Down command:
After being set, the Block Lock bits remain set even after a
hardware reset or power-down/power-up. They are cleared
by a Block Unlock command.
•
The first bus cycle sets up the Block Lock-Down
command.
Refer to "Block Locking," page 37 for a detailed explanation.
See Figure 43, page 77, for a flowchart for using the Lock
command.
•
The second Bus Write cycle latches the block address
and locks-down the block.
The lock status can be monitored for each block using the
Read Electronic Signature command.
Locked-Down blocks revert to the Locked (and not Locked-
Down) state when the device is reset on power-down.
Table 18 shows the Lock Status after issuing a Block Lock-
Down command.
Refer to "Block Locking", for a detailed explanation and
Figure 43, for a flowchart for using the Lock-Down command.
DS617 (v3.0.1) January 07, 2010
www.xilinx.com
Product Specification
17
XILINX [ XILINX, INC ]
