EP2C8Q208C6 Datasheet, PDF (88/168 Pages) Altera Corporation – Section I. Cyclone II Device Family Data Sheet

Power-On Reset Circuitry
For Cyclone II devices, wake-up time consists of power-up, POR,
configuration, and initialization. The device must properly go through all
four stages to configure correctly and begin operation. You can calculate
wake-up time using the following equation:
Wake-Up Time = V_CC Ramp Time + POR Time + Configuration Time + Initialization Time
Figure 4–3 illustrates the components of wake up time.
Figure 4–3. Cyclone II Wake-Up Time
V_CC Minimum
Voltage
V_CC Ramp
Time
POR Time
Note to Figure 4–3:
(1) V_CC ramp must be monotonic.
Configuration Time
Initialization
Time
Time
User
Mode
The V_CC ramp time and POR time will depend on the device
characteristics and the power supply used in your system. The fast-on
devices require a maximum V_CC ramp time of 2 ms and have a maximum
POR time of 12 ms.
Configuration time will depend on the configuration mode chosen and
the configuration file size. You can calculate configuration time by
multiplying the number of bits in the configuration file with the period of
the configuration clock. For fast configuration times, you should use
Passive Serial (PS) configuration mode with maximum DCLK frequency
of 100 MHz. In addition, you can use compression to reduce the
configuration file size and speed up the configuration time. The t_CD2UM
or t_CD2UMC parameters will determine the initialization time.
1
For more information on the t_CD2UM or t_CD2UMC parameters, refer
to the Configuring Cyclone II Devices chapter in the Cyclone II
Device Handbook.
4–6
Cyclone II Device Handbook, Volume 1
Altera Corporation
February 2007