11–22
Altera Corporation
Stratix Device Handbook, Volume 2
July 2005
Configuration Schemes
FPP Configuration Using an Enhanced Configuration Device
When using FPP with an enhanced configuration device, it supplies data
in a byte-wide fashion to the Stratix or Stratix GX device every DCLK
Figure 11–10. FPP Configuration Using Enhanced Configuration Devices
(1)
The pull-up resistors should be connected to the same supply voltage as the
configuration device.
(2)
The enhanced configuration devices and EPC2 devices have internal
programmable pull-ups on OE and nCS. You should only use the internal pull-ups
of the configuration device if the nSTATUS and CONF_DONE signals are pulled up
to 3.3 V or 2.5 V (not 1.8 V or 1.5 V). If external pull-ups are used, they should be
10 k
Ω.
(3)
The nINIT_CONF pin is available on EPC16, EPC8, EPC4, and EPC2 devices. If
nINIT_CONF
is not used, nCONFIG must be pulled to VCC through a resistor. The
nINIT_CONF
pin has an internal pull-up resistor that is always active in EPC16,
EPC8, EPC4, and EPC2 devices. These devices do not need an external pull-up
resistor on the nINIT_CONF pin.
In the enhanced configuration device scheme, nCONFIG is tied to
nINIT_CONF
. On power up, the target Stratix or Stratix GX device senses
the low-to-high transition on nCONFIG and initiates configuration. The
target Stratix or Stratix GX device then drives the open-drain CONF_DONE
pin low, which in-turn drives the enhanced configuration device’s nCS
pin low.
Before configuration starts, there is a 2-ms POR delay if the PORSEL pin
is connected to VCC in the enhanced configuration device. If the PORSEL
pin is connected to ground, the POR delay is 100 ms. When each device
determines that its power is stable, it releases its nSTATUS or OE pin.
Because the enhanced configuration device’s OE pin is connected to the
target Stratix or Stratix GX device’s nSTATUS pin, configuration is
delayed until both the nSTATUS and OE pins are released by each device.
The nSTATUS and OE pins are pulled up by a resistor on their respective
Stratix or
Stratix GX Device
Enhanced
Configuration
Device
DCLK
DATA[7..0]
OE (2)
nCS (2)
nINIT_CONF
(3)
MSEL2
MSEL1
DCLK
DATA[7..0]
nSTATUS
CONF_DONE
nCONFIG
VCC
GND
(1)
nCE
nCEO
N.C.
MSEL0
10 k
Ω
(2)
10 k
Ω
(2)