EP2S90F1020C5 Datasheet, PDF (595/768 Pages) Altera Corporation – Stratix II Device Handbook, Volume 1

Configuring Stratix II and Stratix II GX Devices
Estimating Active Serial Configuration Time
Active serial configuration time is dominated by the time it takes to
transfer data from the serial configuration device to the Stratix II device.
This serial interface is clocked by the Stratix II DCLK output (generated
from an internal oscillator). As listed in Table 7–12 on page 7–37, the DCLK
minimum frequency when choosing to use the 40-MHz oscillator is
20 MHz (50 ns). Therefore, the maximum configuration time estimate for
an EP2S15 device (5 MBits of uncompressed data) is:
RBF Size (minimum DCLK period / 1 bit per DCLK cycle) = estimated
maximum configuration time
5 Mbits × (50 ns / 1 bit) = 250 ms
To estimate the typical configuration time, use the typical DCLK period as
listed in Table 7–12. With a typical DCLK period of 38.46 ns, the typical
configuration time is 192 ms. Enabling compression reduces the amount
of configuration data that is transmitted to the Stratix II or Stratix II GX
device, which also reduces configuration time. On average, compression
reduces configuration time by 50%.
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Programming Serial Configuration Devices
Serial configuration devices are non-volatile, flash-memory-based
devices. You can program these devices in-system using the USB-Blaster^™
or ByteBlaster^™ II download cable. Alternatively, you can program them
using the Altera Programming Unit (APU), supported third-party
programmers, or a microprocessor with the SRunner software driver.
You can perform in-system programming of serial configuration devices
via the AS programming interface. During in-system programming, the
download cable disables device access to the AS interface by driving the
nCE pin high. Stratix II and Stratix II GX devices are also held in reset by
a low level on nCONFIG. After programming is complete, the download
cable releases nCE and nCONFIG, allowing the pull-down and pull-up
resistors to drive GND and V_CC, respectively. Figure 7–15 shows the
download cable connections to the serial configuration device.
For more information on the USB Blaster download cable, refer to the
USB-Blaster Download Cable User Guide. For more information on the
ByteBlaster II cable, refer to the ByteBlaster II Download Cable User Guide.
Altera Corporation
January 2008
7–43
Stratix II Device Handbook, Volume 2