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Figure 7-1: Configuration Sequence for Cyclone V Devices
Power supplies including V
CCPD
and V
CCPGM
reach
recommended operating voltage
nSTATUS and nCONFIG released high
CONF_DONE pulled low
CONF_DONE released high
INIT_DONE released high
(if option enabled)
Power Up
•
nSTATUS
and
CONF_DONE
driven low
• All I/Os pins are tied to an
internal weak pull-up
• Clears configuration RAM bits
Reset
•
nSTATUS
and
CONF_DONE
remain low
• All I/Os pins are tied to an
internal weak pull-up
• Samples
MSEL
pins
Initialization
• Initializes internal logic and
registers
• Enables I/O buffers
Configuration Error Handling
•
nSTATUS
pulled low
•
CONF_DONE
remains low
• Restarts configuration if option
enabled
User Mode
Executes your design
Configuration
Writes configuration data to
FPGA
You can initiate reconfiguration by pulling the
nCONFIG
pin low to at least the minimum t
CFG
low-pulse
width except for configuration using the partial reconfiguration operation. When this pin is pulled low, the
nSTATUS
and
CONF_DONE
pins are pulled low and all I/O pins are tied to an internal weak pull-up.
Power Up
Power up all the power supplies that are monitored by the POR circuitry. All power supplies, including
V
CCPGM
and V
CCPD
, must ramp up from 0 V to the recommended operating voltage level within the ramp-
up time specification. Otherwise, hold the
nCONFIG
pin low until all the power supplies reach the recommended
voltage level.
V
CCPGM
Pin
The configuration input buffers do not have to share power lines with the regular I/O buffers in Cyclone V
devices.
Configuration, Design Security, and Remote System Upgrades in Cyclone V Devices
Altera Corporation
CV-52007
Power Up
7-4
2014.01.10