EP3C16F256I7N Altera, EP3C16F256I7N Datasheet - Page 250

• Manufacturer Part Number: EP3C16F256I7N
• Description: Cyclone III
• Manufacturer: Altera

Configuring Cyclone III Devices
Active Serial
Configuration
(Serial
Configuration
Devices)
10–14
Cyclone III Device Handbook, Volume 1
f
f
All I/O inputs must maintain a maximum AC voltage of 4.1 V. When
using a serial configuration device in the AS configuration scheme, you
must connect a 25-Ω series resistor at the near end of the serial
configuration device for the DATA[0]. When cascading Cyclone III
devices in multi-device configuration, you must connect repeater buffers
between the Cyclone III master and slave device(s) for DATA and DCLK.
The output resistance of the repeater buffers has to fit the maximum
overshoot equation given by: 0.8Z
In this equation Z
equivalent resistance of the output buffer.
In the AS configuration scheme, Cyclone III devices are configured using
a serial configuration device. These configuration devices are low-cost
devices with non-volatile memory that feature a simple four-pin interface
and a small form factor. These features make serial configuration devices
an ideal low-cost configuration solution.
For more information on serial configuration devices, refer to the Serial
Configuration Devices (EPCS1, EPCS4, EPCS16 and EPCS64) Data Sheet in
the Configuration Handbook.
In Cyclone III devices, the active master clock frequency runs at a
maximum of 40 MHz, and around a typical 30 MHz. Cyclone III devices
only work with serial configuration devices that support up to 40 MHz.
Existing batches of EPCS4 manufactured on 0.15 µm process geometry
supports AS configuration in Cyclone III devices up to 40 MHz. However,
batches of EPCS4 manufactured on 0.18 µm process geometry support
only up to 20 MHz. EPCS16 and EPCS64 serial configuration devices are
not affected.
For information about product traceability and transition date to
differentiate between 0.15 μm process geometry and 0.18 μm process
geometry EPCS4 serial configuration devices, refer to PCN 0514
Manufacturing Changes on EPCS Family process change notification on the
Altera website at www.altera.com.
Serial configuration devices provide a serial interface to access
configuration data. During device configuration, Cyclone III devices read
configuration data via the serial interface, decompress data if necessary,
and configure their SRAM cells. This scheme is referred to as the AS
configuration scheme because the device controls the configuration
interface. This scheme contrasts with the PS configuration scheme, where
the external host controls the interface.
O
is the transmission line impedence and R
O
≤ R
E
≤ 1.8Z
Altera Corporation-Preliminary
O
E
March 2007
is the