EP2C8T144I8N Datasheet, PDF (383/470 Pages) Altera Corporation – Cyclone II Device Handbook, Volume 1

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 nCE pins 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
nCEO pin 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 DCLK and DATA lines 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
ADDR
DATA0
External Host
(MAX II Device
or Microprocessor)
VCC (1) VCC (1)
10 kΩ 10 kΩ
GND
VCC
Cyclone II Device
MSEL1
MSEL0
CONF_DONE
nSTATUS
nCE
nCEO
GND
N.C. (3)
VCC
Cyclone II Device
MSEL1
MSEL0
CONF_DONE
nSTATUS
nCE
GND
DATA0
nCONFIG
DCLK
GND
DATA0
nCONFIG
DCLK
nCEO N.C. (2)
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. V_CC should be high enough to meet the V_IH specification of the I/O on the devices and the external host.
(2) The nCEO pins of both devices can be left unconnected or used as user I/O pins when configuring the same
configuration data into multiple devices.
f
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_DONE and nSTATUS pins 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.
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