
7–64
Altera Corporation
Stratix II Device Handbook, Volume 2
January 2008
Passive Serial Configuration
configuration at the same time.
Figure 7–24 shows multi-device PS
configuration when the Stratix II or Stratix II GX devices are receiving the
same configuration data.
Figure 7–24. Multiple-Device PS Configuration Using an Enhanced Configuration Device When devices
Receive the Same Data
(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, meaning 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-ups on configuration device
option when generating programming files.
(4)
The nCEO pins of all devices are left unconnected when configuring the same configuration data into multiple
devices.
DCLK
DATA0
nCONFIG
VCC
GND
(3)
nCE
(3)
VCC
DCLK
DATA0
nSTATUS
CONF_DONE
nCONFIG
nCE
nSTATUS
CONF_DONE
DCLK
DATA0
nCONFIG
nCE
GND
Stratix II or Stratix II GX
Device 1
Stratix II or Stratix II GX
Device 2
Last Stratix II or Stratix II GX
Device
DCLK
DATA0
OE
nCS
nINIT_CONF (2)
nSTATUS
CONF_DONE
N.C.
nCEO
N.C.
nCEO
N.C.
nCEO
(4)
(1)
10 K
Ω
10 K
Ω
(3)
Enhanced
Configuration
Device
MSEL1
MSEL0
GND
MSEL3
MSEL2
VCC
MSEL1
MSEL0
GND
MSEL3
MSEL2
VCC
MSEL1
MSEL0
GND
MSEL3
MSEL2
VCC