EP2AGX95EF29C6N Datasheet, PDF (309/380 Pages) Altera Corporation – Device Interfaces and Integration

Chapter 9: Configuration, Design Security, and Remote System Upgrades in Arria II Devices
AS and Fast AS Configuration (Serial Configuration Devices)
9–23
Guidelines for Connecting Serial Configuration Device to Arria II Devices
on an AS Interface
For single- and multi-device AS configurations, the board trace length and loading
between the supported serial configuration device and the Arria II devices must
follow the recommendations listed in Table 9–11.
Table 9–11. Maximum Trace Length and Loading for the AS Configuration in Arria II Devices
Arria II Device AS Pins
DCLK
DATA[0]
nCSO
ASDO
Maximum Board Trace Length from
the Arria II Device to the Serial
Configuration Device (Inches)
10
10
10
10
Maximum Board Load (pF)
15
30
30
30
Estimating the AS Configuration Time
AS configuration time is dominated by the time it takes to transfer data from the serial
configuration device to the Arria II device. This serial interface is clocked by the
Arria II DCLK output (generated from an internal oscillator or an option to select
CLKUSR as external clock source). Arria II devices support DCLK up to 40 MHz
(25 ns).
Therefore, you can estimate the minimum configuration time as the following:
RBF Size × (minimum DCLK period / 1 bit per DCLK cycle) = estimated minimum
configuration time.
Enabling compression reduces the amount of configuration data that is transmitted to
the Arria II device, which also reduces configuration time. On average, compression
reduces configuration time, depending on your design.
July 2012 Altera Corporation
Arria II Device Handbook Volume 1: Device Interfaces and Integration