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【应用手册】Cyclone III Configuration Interface Guidelines with EPCS Devices
This application note describes the methods to interface a Cyclone III®
device to a serial configuration device (EPCS) using Cyclone III I/O
voltages of 3.0 V and 2.5 V, in addition to the standard 3.3 V. This
application note discusses the electrical specifications, timing
requirements, signal integrity analysis, and board physical design
guidelines for the supported active serial (AS) configuration schemes.
On Cyclone III devices, bank 1 is used for AS configuration signals and
for user I/Os. The I/O voltage for Cyclone III AS configuration signals
must be compatible with the operating voltage of Altera EPCS devices
and must not conflict with the intended I/O voltages for other bank 1
signals. The Altera EPCS devices support supply voltage from 2.7 V to
3.6 V, which enables it to be operated at 3.3 V or 3.0 V. This application
note shows the methods to use the Cyclone III bank 1 I/O voltages of
3.0 V and 2.5 V with the EPCS device.
Additionally, at any of the Cyclone III I/O voltages of 3.3/3.0/2.5 V, this
application note shows how to create a robust electrical and physical
board design to interface with an EPCS device using single and multidevice
AS configuration. You can create your design based on the signal
integrity analysis and physical design constraints in this application note
to achieve a successful AS configuration.AN523.pdf