Temperature-Sensing Diode
You can implement the error detection CRC feature with existing
circuitry in Stratix GX devices, eliminating the need for external logic. For
Stratix GX devices, the CRC is computed by Quartus II and downloaded
into the device as a part of the configuration bit stream. The CRC_ERROR
pin reports a soft error when configuration SRAM data is corrupted,
triggering device reconfiguration.
Custom-Built Circuitry
Dedicated circuitry is built into Stratix GX devices to perform error
detection automatically. This error detection circuitry constantly checks
for errors in the configuration SRAM cells while the device is in user
mode. You can monitor one external pin for the error and use it to trigger
a reconfiguration cycle. You can select the desired time between checks
by adjusting a built-in clock divider.
Software Interface
In the Quartus II software version 4.1 and later, you can turn on the
automated error detection CRC feature in the Device & Pin Options
dialog box. This dialog box allows you to enable the feature and set the
internal frequency of the CRC between 400 kHz to 100 MHz. This
controls the rate that the CRC circuitry verifies the internal configuration
SRAM bits in the FPGA device.
For more information on CRC, refer to AN 357: Error Detection Using CRC
in Altera FPGA Devices.
Stratix GX devices include a diode-connected transistor for use as a
temperature sensor in power management. This diode is used with an
external digital thermometer device such as a MAX1617A or MAX1619
from MAXIM Integrated Products. These devices steer bias current
through the Stratix GX diode, measuring forward voltage and converting
this reading to temperature in the form of an 8-bit signed number (7 bits
plus sign). The external device’s output represents the package
temperature of the Stratix GX device and can be used for intelligent
power management.
Temperature-
Sensing Diode
The diode requires two pins (tempdiodepand tempdioden) on the
Stratix GX device to connect to the external temperature-sensing device,
as shown in Figure 5–4. The temperature-sensing diode is a passive
element and therefore can be used before the Stratix GX device is
powered.
5–8
Altera Corporation
Stratix GX Device Handbook, Volume 1
February 2005
ALTERA [ ALTERA CORPORATION ]
