Configuring Cyclone II Devices
When designing a Cyclone II board for JTAG configuration, use the
guidelines in Table 13–10 for the placement of the dedicated
configuration pins.
Table 13–10. Dedicated Configuration Pin Connections During JTAG
Configuration
Signal
Description
nCE
On all Cyclone II devices in the chain, nCEshould be driven
low by connecting it to ground, pulling it low via a resistor, or
driving it by some control circuitry. For devices that are also in
multiple device AS, or PS configuration chains, the nCEpins
should be connected to GND during JTAG configuration or
JTAG configured in the same order as the configuration chain.
nCEO
MSEL
On all Cyclone II devices in the chain, nCEOcan be used as a
user I/O or connected to the nCEof the next device. If nCEOis
connected to the nCEof the next device, the nCEOpin must
be pulled high to VCCIO by an external 10-kΩ pull-up resistor
to help the internal weak pull-up resistor. If the nCEOpin is not
connected to the nCEpin of the next device, you can use it as
a user I/O pin after configuration.
These pins must not be left floating. These pins support
whichever non-JTAG configuration is used in production. If
only JTAG configuration is used, you should tie these pins to
ground.
Driven high by connecting to VCC, pulling up via a resistor, or
driven high by some control circuitry.
nCONFIG
nSTATUS
Pull to VCC via a 10-kΩ resistor. When configuring multiple
devices in the same JTAG chain, each nSTATUSpin should
be pulled up to VCC individually. nSTATUSpulling low in the
middle of JTAG configuration indicates that an error has
occurred.
Pull to VCC via a 10-kΩ resistor. When configuring multiple
CONF_DONE
DCLK
devices in the same JTAG chain, each CONF_DONEpin
should be pulled up to VCC individually. CONF_DONEgoing
high at the end of JTAG configuration indicates successful
configuration.
Should not be left floating. Drive low or high, whichever is more
convenient on your board.
Figure 13–23 shows JTAG configuration of a Cyclone II device with a
microprocessor.
Altera Corporation
February 2007
13–57
Cyclone II Device Handbook, Volume 1
ALTERA [ ALTERA CORPORATION ]
