Altera Corporation
7–31
January 2008
Stratix II Device Handbook, Volume 2
Configuring Stratix II and Stratix II GX Devices
pulled low, this activates the configuration device because it sees its nCS
pin drive low. Once nCONFIG returns to a logic high level and nSTATUS
is released by the device, reconfiguration begins.
Figure 7–9 shows how to configure multiple Stratix II or Stratix II GX
devices with an enhanced configuration device. This circuit is similar to
the configuration device circuit for a single device, except the Stratix II or
Stratix II GX devices are cascaded for multi-device configuration.
Figure 7–9. Multi-Device FPP Configuration Using an Enhanced Configuration Device
(1)
The pull-up resistor should be connected to the same supply voltage as the configuration device.
(2)
The nINIT_CONF pin is available on enhanced configuration devices and has an internal pull-up resistor that is
always active. This means an external pull-up resistor should not be used on the nINIT_CONF-nCONFIG line. The
nINIT_CONF
pin does not need to be connected if its functionality is not used. If nINIT_CONF is not used, nCONFIG
must be pulled to VCC either directly or through a resistor.
(3)
The enhanced configuration devices’ OE and nCS pins have internal programmable pull-up resistors. If internal
pull-up resistors are used, external pull-up resistors should not be used on these pins. The internal pull-up resistors
are used by default in the Quartus II software. To turn off the internal pull-up resistors, check the Disable nCS and
OE pull-up resistors on configuration device
option when generating programming files.
1
Enhanced configuration devices cannot be cascaded.
When performing multi-device configuration, you must generate the
configuration device’s POF from each project’s SOF. You can combine
multiple SOFs using the Convert Programming Files window in the
Quartus II software.
f
For more information on how to create configuration files for
of the Configuration Handbook.
nCS
DATA[7..0]
OE
nINIT_CONF (2)
GND
10 k
Ω
DCLK
VCC (1)
(3)
10 k
Ω
VCC (1)
(3)
Enhanced
Configuration Device
CONF_DONE
DATA[7..0]
nSTATUS
nCONFIG
DCLK
MSEL[3..0]
nCE
nCEO
Stratix II Device 1
CONF_DONE
DATA[7..0]
nSTATUS
nCONFIG
DCLK
MSEL[3..0]
nCE
N.C.
nCEO
Stratix II Device 2
(3)