Configuring Cyclone II Devices
If your system has multiple Cyclone II devices (in the same density and
package) with the same configuration data, you can configure them in
one configuration cycle by connecting all device’s nCEpins to ground and
connecting all the Cyclone II device’s configuration pins (nCONFIG,
nSTATUS, DCLK, DATA0, and CONF_DONE) together. You can also use the
nCEOpin as a user I/O pin after configuration. The configuration signals
may require buffering to ensure signal integrity and prevent clock skew
problems. Make sure the DCLKand DATAlines are buffered for every
fourth device. All devices start and complete configuration at the same
time. Figure 13–11 shows multiple device PS configuration when both
Cyclone II devices are receiving the same configuration data.
Figure 13–11. Multiple Device PS Configuration When Both FPGAs Receive the Same Data
Memory
V
(1)
V
(1)
CC
CC
V
V
CC
ADDR
DATA0
CC
Cyclone II Device
Cyclone II Device
10 kΩ
10 kΩ
MSEL1
MSEL1
MSEL0
MSEL0
CONF_DONE
nSTATUS
CONF_DONE
nSTATUS
GND
N.C. (3)
GND
nCE
nCE
nCEO
External Host
(MAX II Device
or Microprocessor)
GND
nCEO
N.C. (2)
GND
DATA0
DATA0
nCONFIG
DCLK
nCONFIG
DCLK
Notes to Figure 13–11:
(1) The pull-up resistor should be connected to a supply that provides an acceptable input signal for all devices in the
chain. VCC should be high enough to meet the VIH specification of the I/O on the devices and the external host.
(2) The nCEOpins of both devices can be left unconnected or used as user I/O pins when configuring the same
configuration data into multiple devices.
You can use a single configuration chain to configure Cyclone II devices
with other Altera devices. Connect all the Cyclone II device’s and all
other Altera device’s CONF_DONEand nSTATUSpins together so all
devices in the chain complete configuration at the same time or that an
error reported by one device initiates reconfiguration in all devices.
f
For more information on configuring multiple Altera devices in the same
configuration chain, see Configuring Mixed Altera FPGA Chains in the
Configuration Handbook.
Altera Corporation
February 2007
13–29
Cyclone II Device Handbook, Volume 1
ALTERA [ ALTERA CORPORATION ]
