Hotchips 22: ARMv7-A Extensions
SAN JOSE, Calif. -- Mindspeed described a new family of system-on-chip processors for cellular basestations at Hot Chips. The first member of the Transcede family uses as many as 26 processor cores including four ARM Cortex-A9 cores, 10 CEVA DSP cores and nine DSP accelerators to compete with a host of basestation chip makers including Texas Instruments and Freescale.
The Transcede 4000 will run at data rates up to 750 MHz and consume 12W average in a 40nm TSMC process. The 300 million transistor chip uses an ARM AXI network on-chip to link its cores and peripherals internally and integrates 9.1 Mbytes of L1 and L2 caches. It uses a combination of 10 high-speed serdes, PCI Express and serial Rapid I/O for external links.
Transcede is geared for a variety of wireless protocols including LTE, W-CDMA and WiMax. Mindspeed uses C programming for Transcede, but implements a new modeling approach for application partitioning and profiling early in the design phase.
"We built a composer tool that looks at resources and dependencies and figures out how to set parameters for a task scheduler," said Jim Johnston, chief technology officer at Mindspeed.
The company maps the job of running an LTE physical layer function across multiple cores including the Cortex A9, Ceva X1641 and Mindspeed Application Processor cores. The company will roll members of the family with different numbers of cores, amounts of memory and I/O to target everything from large outdoor basestations to home femtocells.
A wide variety of companies are developing competing chips including TI and Freescale which currently use six DSP cores on a die, said Will Strauss, principal of market watcher Forward Concepts (Tempe, Az.).
In addition, "Tensilica has announced that three of its Japanese licensees are developing LTE basebands based on at least six of their Xtensa cores for LTE modems," said Strauss. "Qualcomm has been using two of its own DSP cores in its baseband chips for at least three years, and rumor has it that it is developing a new modem based on even more DSP cores maybe at its Austin, Texas development center," he said.
Infineon has recently licensed new DSP cores from CEVA for a future multichip LTE baseband and several WiMax chip designers are also working on LTE basebands, he added.
Mindspeed CTO Jim Johnston presents the company's Transcede basestation processor