Specifications

Security Key Types
Cyclone V devices offer two types of keys—volatile and non-volatile. The following table lists the differences
between the volatile key and non-volatile keys.
Table 7-9: Security Key Types
Programming MethodPower Supply for Key
Storage
Key ProgrammabilityKey Types
On-boardRequired external
battery, V
CCBAT
(18)
• Reprogrammable
• Erasable
Volatile
On-board and in-socket
programming
(19)
Does not require an
external battery
One-time program-
ming
Non-volatile
Both non-volatile and volatile key programming offers protection from reverse engineering and copying. If
you set the tamper-protection bit, the design is also protected from tampering.
You can perform key programming through the JTAG pins interface. Ensure that the nSTATUS pin is
released high before any key-programming attempts.
To clear the volatile key, issue the KEY_CLR_VREG JTAG instruction. To verify the volatile key has
been cleared, issue the KEY_VERIFY JTAG instruction.
Note:
Related Information
• Supported JTAG Instruction on page 9-3
Provides more information about the KEY_CLR_VREG and KEY_VERIFY instructions.
• JTAG Boundary-Scan Testing in Cyclone V Devices
Provides more information about the KEY_CLR_VREG and KEY_VERIFY JTAG instructions.
• Cyclone V Device Family Pin Connection Guidelines
Provides more information about the V
CCBAT
pin connection recommendations.
• Cyclone V Device Datasheet
Provides more information about battery specifications.
Security Modes
Table 7-10: Supported Security Modes
Security LevelDevice Accepts
Encrypted File
Device Accepts
Unencrypted File
Tamper Protection
Bit Setting
Security Mode
—NoYes—No key
SecureYesYes—Volatile Key
(18)
V
CCBAT
is a dedicated power supply for volatile key storage. V
CCBAT
continuously supplies power to the volatile
register regardless of the on-chip supply condition.
(19)
Third-party vendors offer in-socket programming.
Altera Corporation
Configuration, Design Security, and Remote System Upgrades in Cyclone V Devices
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7-35
Security Key Types
CV-52007
2013.06.11