23 February 2006
An inside job
It’s what’s diffused that makes the difference. By Philip Ling.
You have to hand it to fpga companies: they’re not afraid to try something different. And, in a conservative industry like semiconductor fabrication, trying something different isn’t always encouraged – especially when it involves a lot of NRE cost and effort. But that’s exactly what they did when they chose to integrate microprocessor cores in their fpga fabrics.
In truth, when the first fpgas with diffused processors started to appear, it seemed like we’d been waiting forever to see them. Professional observers thought it such an obvious direction to move in that they couldn’t understand the delay. When at last they were revealed, they were received with enthusiasm and great expectations.
But the industry didn’t seem to share that enthusiasm and expectations failed to be met. Although all mainstream fpga vendors bought into the idea of embedded cores in one way or another, they have in similar fashion abandoned the concept to a greater or lesser extent.
For instance, Altera still supplies Excalibur devices – essentially an APEX20KE with an ARM9 core diffused in it – but they aren’t recommended for new designs. Instead, Altera recommends the adoption of its proprietary soft core NIOS, which isn’t restricted to the APEX family.
Likewise, Atmel still offers its FPSLIC (field programmable system level integrated circuit), which is based on an 8bit AVR microcontroller embedded in an AT40K fpga. But it hasn’t developed the family beyond the AT94S secure version of the standard AT94K. Only Xilinx stands resolute in its continued diffusion of PowerPC cores into its Virtex II Pro and Virtex4 FX families. However, when Virtex II was first announced, there were plans to offer variants with one, two and four PowerPC cores, since restricted to a maximum of two. Similarly, Virtex4 is available with up to two PowerPC405 cores.
Author
Graham Pitcher
Supporting Information
Downloads
5685\an-inside-job.pdf
Websites
http://www.actel.com
http://www.altera.com
http://www.arm.com
http://www.atmel.com
http://www.xilinx.com
Companies
Altera UK Ltd
ARM Ltd
Atmel UK Ltd
Microsemi
Xilinx Ltd
This material is protected by Findlay Media copyright
See Terms
and Conditions.
One-off usage is permitted but bulk copying is not.
For multiple copies contact the
sales team.