HC20K400 Datasheet, PDF (13/36 Pages) Altera Corporation – HardCopy APEX Device Family

Differences Between HardCopy APEX and APEX 20K FPGAs
Differences
Between
HardCopy APEX
and APEX 20K
FPGAs
Several differences must be considered before a design is ready for
implementation in HardCopy technology:
■ HardCopy APEX devices are only customizable at the time they are
manufactured. Make sure that the original APEX 20KE or
APEX 20KC device has undergone thorough testing in the
end-system before deciding to proceed with migration to a
HardCopy APEX device, because no changes can be made to the
HardCopy APEX device after it has been manufactured.
■ ESBs that are configured as RAM or CAM will power-up
un-initialized in the HardCopy APEX device. In the FPGA it is
possible to configure, or “pre-load,” the ESB memory as part of the
configuration sequence, then overwrite it when the device is in
normal functional mode. This pre-loaded memory feature of the
FPGA is not available in HardCopy devices. If a design contains
RAM or CAM with assumed data values at power-up, then the
HardCopy APEX device will not operate as expected. If a design uses
this feature, it should be re-compiled without the memory pre-load.
ESBs configured as ROM are fully supported.
■ The JTAG boundary scan order in the HardCopy APEX device is
different compared to the APEX 20K device. A HardCopy BSDL file
that describes the re-ordered boundary scan chain should be used.
1
The BSDL files for HardCopy APEX devices are different
from the corresponding APEX 20KE or APEX 20KC
devices. Download the correct HardCopy BSDL file from
Altera’s website at www.altera.com.
■ The advanced 0.18-μm aluminum metal process is used to support
both APEX 20KE and APEX 20KC devices. The performance
improvement achieved by the die size reduction and metal
interconnect optimization more than offsets the need for copper in
this case. Altera guarantees that a target HardCopy APEX device will
provide the same or better performance as in the corresponding
APEX 20KE or APEX 20KC device.
Power-up Mode
and
Configuration
Emulation
Unlike their FPGA counterparts, HardCopy APEX devices do not need to
be configured. However, to facilitate seamless migration, configuration
can be emulated in these devices. There are three modes in which a
Altera Corporation
8–5
September 2008