EP4CE55F23C7 Altera, EP4CE55F23C7 Datasheet - Page 267

• Manufacturer Part Number: EP4CE55F23C7
• Description: IC CYCLONE IV FPGA 55K 484FBGA
• Manufacturer: Altera
• Series: CYCLONE® IV Er

Specifications of EP4CE55F23C7

• Number Of Logic Elements/cells: 55856
• Number Of Labs/clbs: 3491
• Total Ram Bits: 2340000
• Number Of I /o: 324
• Voltage - Supply: 1.15 V ~ 1.25 V
• Mounting Type: Surface Mount
• Operating Temperature: 0°C ~ 85°C
• Package / Case: 484-FBGA
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Number Of Gates: -

Chapter 11: Power Requirements for Cyclone IV Devices
Hot-socketing Feature Implementation
Hot-socketing Feature Implementation
Power-On Reset Circuitry
© July 2010 Altera Corporation
f
1
1
The user I/O pins and dual-purpose I/O pins have weak pull-up resistors, which are
always enabled (after POR) before and during configuration. The weak pull up
resistors are not enabled prior to POR.
A possible concern for semiconductor devices in general regarding hot socketing is
the potential for latch up. Latch up can occur when electrical subsystems are hot
socketed into an active system. During hot socketing, the signal pins may be
connected and driven by the active system before the power supply can provide
current to the V
and cause a low-impedance path from V
device extends a large amount of current, possibly causing electrical damage.
The design of the I/O buffers and hot-socketing circuitry ensures that Cyclone IV
devices are immune to latch up during hot-socketing.
For more information about the hot-socketing specification, refer to the
Device Datasheet
for Altera Devices
The hot-socketing circuit does not include the CONF_DONE, nCEO, and nSTATUS pins
to ensure that they are able to operate during configuration. The expected behavior
for these pins is to drive out during power-up and power-down sequences.
Altera uses GND as reference for hot-socketing operation and I/O buffer designs. To
ensure proper operation, Altera recommends connecting the GND between boards
before connecting the power supplies. This prevents the GND on your board from
being pulled up inadvertently by a path to power through other components on your
board. A pulled up GND can otherwise cause an out-of-specification I/O voltage or
current condition with the Altera device.
Cyclone IV devices contain POR circuitry to keep the device in a reset state until the
power supply voltage levels have stabilized during power up. During POR, all user
I/O pins are tri-stated until the power supplies reach the recommended operating
levels. In addition, the POR circuitry also ensures the V
contain configuration pins reach an acceptable level before configuration is triggered.
The POR circuit of the Cyclone IV device monitors the V
contain configuration pins during power-on. You can power up or power down the
V
monotonic rise to their steady state levels. All V
(even when PLLs are not used), and must be powered up and powered down at the
same time.
After the Cyclone IV device enters the user mode, the POR circuit continues to
monitor the V
detected. If the V
mode, the POR circuit resets the device. If the V
the POR circuit does not reset the device.
CCINT
, V
CCA
, and V
CCINT
CC
chapter and the
white paper.
CCINT
of the device and ground planes. This condition can lead to latch up
CCIO
and V
or V
pins in any sequence. The V
CCA
CCA
pins so that a brown-out condition during user mode is
voltage sags below the POR trip point during user
Hot-Socketing and Power-Sequencing Feature and Testing
CC
to GND in the device. As a result, the
CCA
CCIO
CCINT
pins must be powered to 2.5V
voltage sags during user mode,
, V
CCIO
CCINT
CCA
Cyclone IV Device Handbook, Volume 1
level of I/O banks that
, and V
, V
CCA
, and V
CCIO
must have a
Cyclone IV
CCIO
that
11–3