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If you do not turn on this option, you can monitor the
nSTATUS
pin to detect errors. To restart configuration,
pull the
nCONFIG
pin low for at least the duration of t
CFG
.
Related Information
Provides more information about t
STATUS
and t
CFG
timing parameters.
Initialization
The initialization clock source is from the internal oscillator,
CLKUSR
pin, or
DCLK
pin. By default, the internal
oscillator is the clock source for initialization. If you use the internal oscillator, the Cyclone V device will be
provided with enough clock cycles for proper initialization.
If you use the optional
CLKUSR
pin as the initialization clock source and the
nCONFIG
pin is pulled
low to restart configuration during device initialization, ensure that the
CLKUSR
or
DCLK
pin continues
toggling until the
nSTATUS
pin goes low and then goes high again.
Note:
The
CLKUSR
pin provides you with the flexibility to synchronize initialization of multiple devices or to delay
initialization. Supplying a clock on the
CLKUSR
pin during initialization does not affect configuration. After
the
CONF_DONE
pin goes high, the
CLKUSR
or
DCLK
pin is enabled after the time specified by t
CD2CU
. When
this time period elapses, Cyclone V devices require a minimum number of clock cycles as specified by T
init
to initialize properly and enter user mode as specified by the t
CD2UMC
parameter.
Related Information
Provides more information about t
CD2CU
, t
init
, and t
CD2UMC
timing parameters, and initialization clock
source.
User Mode
You can enable the optional
INIT_DONE
pin to monitor the initialization stage. After the
INIT_DONE
pin is
pulled high, initialization completes and your design starts executing. The user I/O pins will then function
as specified by your design.
Device Configuration Pins
Configuration Pins Summary
The following table lists the Cyclone V configuration pins and their power supply.
The
TDI
,
TMS
,
TCK
, and
TDO
pins are powered by V
CCPD
of the bank in which the pin resides.
Note:
The
CLKUSR
,
DEV_OE
,
DEV_CLRn
, and
DATA[15..5]
pins are powered by V
CCPGM
during configuration
and by V
CCIO
of the bank in which the pin resides if you use it as a user I/O pin.
Note:
Configuration, Design Security, and Remote System Upgrades in Cyclone V Devices
Altera Corporation
CV-52007
Initialization
7-6
2014.01.10