ep2s130 Altera Corporation, ep2s130 Datasheet - Page 134

• Manufacturer Part Number: ep2s130
• Description: Stratix Ii Device Family Data Sheet
• Manufacturer: Altera Corporation

Hot Socketing Feature Implementation in Stratix II Devices
4–4
Stratix II Device Handbook, Volume 1
Figure 4–1. Hot Socketing Circuit Block Diagram for Stratix II Devices
The POR circuit monitors V
stated until the device is in user mode. The weak pull-up resistor (R) from
the I/O pin to V
3.3-V tolerance control circuit permits the I/O pins to be driven by 3.3 V
before V
the I/O pins from driving out when the device is not in user mode. The
hot socket circuit prevents I/O pins from internally powering V
V
powered.
Figure 4–2
I/O buffers. This design ensures that the output buffers do not drive
when V
than V
insertion. There is no current path from signal I/O pins to V
or V
tolerant circuit capacitance.
CCINT
Resistor
Pull-Up
CCPD
Weak
PAD
, and V
CCIO
CCIO
CCIO
during hot insertion. The V
. This also applies for sudden voltage spikes during hot
shows a transistor level cross section of the Stratix II device
is powered before V
and/or V
CCPD
R
CCIO
when driven by external signals before the device is
Output
is present to keep the I/O pins from floating. The
CCINT
CCINT
and/or V
CCINT
voltage level and keeps I/O pins tri-
PAD
Input Buffer
to Logic Array
CCPD
Tolerance
or if the I/O pad voltage is higher
Voltage
Control
leakage current charges the 3.3-V
are powered, and it prevents
Output Enable
Altera Corporation
Hot Socket
Pre-Driver
Output
CCINT
Power On
Monitor
Reset
May 2007
CCIO
or V
,
CCIO