EP2C5T144I8N Datasheet, PDF (387/470 Pages) Altera Corporation – Cyclone II Device Handbook, Volume 1

Configuring Cyclone II Devices
Figure 13–13. Single Device PS Configuration Using an Enhanced
Configuration Device
Cyclone II FPGA
VCC
MSEL0
MSEL1
DCLK
DATA0
nSTATUS
CONF_DONE
nCONFIG
nCEO
nCE
VCC ₍₁₎ VCC (1) VCC ₍₁₎
10 kΩ
10 kΩ 10 kΩ
Enhanced
Configuration
Device
DCLK
DATA
OE (3)
nCS (3)
nINIT_CONF (2)
N.C. (4)
GND
GND
Notes to Figure 13–13:
(1) The pull-up resistor should be connected to the same supply voltage as the
configuration device. This pull-up resistor is 10 kΩ.
(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 to 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 V_CC either directly or through a resistor (if
reconfiguration is required, a resistor is necessary).
(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 pin can be left unconnected or used as a user I/O pin when it does not
feed other device’s nCE pin.
f
The value of the internal pull-up resistors on the enhanced configuration
devices and EPC2 devices can be found in the Enhanced Configuration
Devices (EPC4, EPC8, & EPC16) Data Sheet or the Configuration Devices for
SRAM-based LUT Devices Data Sheet.
When using enhanced configuration devices or EPC2 devices, you can
connect the Cyclone II nCONFIG pin to the configuration device
nINIT_CONF pin, which allows the INIT_CONF JTAG instruction to
initiate FPGA configuration. You do not need to connect the
nINIT_CONF pin if you are not using it. If nINIT_CONF is not used or not
available (e.g., on EPC1 devices), pull the nCONFIG signal to V_CC either
directly or through a resistor (if reconfiguration is required, a resistor is
necessary). An internal pull-up resistor on the nINIT_CONF pin is always
active in enhanced configuration devices and EPC2 devices. Therefore,
you do not need an external pull-up if nCONFIG is connected to
nINIT_CONF.
Altera Corporation
February 2007
13–33
Cyclone II Device Handbook, Volume 1