DSPs promise cost, power savings

Dubbed the TMS320VC5504 and 'C5505, the processors are a major leap forward in almost all respects from their predecessor, the 'C5509. While including 320Kbyte on-chip memory, a USB 2.0 interface, hardware FFT and UART, an LCD interface and myriad I/O and peripheral support, the chips also manage to reduce power consumption—and cost—versus the 'C5509.

According to Srik Gurrapu, product marketing manager at TI, the biggest single enabler to the new designs was the move from the 'C5509's 130nm process to a low-leakage 90nm process, along with custom libraries. This brought the active power down from 0.54mW/MHz to 0.3mW/MHz, with 75 percent dual MAC and 25 percent addition operations.

In addition, the low-leakage process keeps the standby power to less than 340?W. This can go 30 percent lower using retention mode, according to Gurrapu.

In total, factoring in the integration of the memory, USB and LCD interface, Gurrapu estimates a 40 percent reduction in total system power and a corresponding 40 percent increase in battery life. "In reality, the savings will be even higher due to other improvements such as the FFT accelerator providing even higher energy efficiency," he said. For more specifics on the FFT hardware accelerator's capabilities, click here.

The two new ICs are differentiated essentially in terms of functional integration and cost but are fully pin compatible. Both have a dual-MAC, 'C55x CPU core that runs off 1.05V at 60MHz and 1.3V at 100MHz, as well as a plethora of I/O and peripheral support, including a fully USB 2.0 physical layer.

While the 'C5504 has 256Kbyte of on-chip memory and costs $5.60 each in quantities of 1,000, the 'C5505 has 320 Kbytes, along with an up to 1,024-point programmable FFT hardware accelerator, integrated LCD display controller and a 10bit four-channel SAR ADC. It costs $6.75 each per 1,000.

To help customers get started quickly, TI is also announcing the C5505 DSP EVM that can be used with both the C5505 and C5504 processors and comes ready with application demos and code.

- Patrick Mannion
DSP DesignLine