Math with a twist
-- EDN, January 20, 2000
Regardless of whether you can use QuickLogic's QuickDSP chips (Picture), you have to give the company credit for creative interpretation of the term "digital-signal processing." QuickDSP is the second of QuickLogic's embedded-standard-product family; the first, QuickPCI, combines a range of ASIC-based PCI cores with RAM blocks and antifuse-based user-programmable logic. This time around, the company devotes the ASIC gates to arithmetic circuits, which it calls embedded computational units (ECUs). Each ECU can implement several single-pass asynchronous and registered functions (8x8-bit multiply, 16-bit add, or accumulate with carry) with multiple passes through the ECU supporting the common multiply/accumulate function.
QuickLogic claims that hard-coded ASIC ECUs implement arithmetic operations at much higher speeds with lower power and reduced die area and cost than programmable look-up-table- or multiplexer-based alternatives. Specifications include a 4.53-nsec multiply, 2.54-nsec add, and 7.07-nsec multiply/add. The ECUs' 3-bit instruction-input bus, which your programmable-logic-based state machine or another circuit drives, selects the appropriate mode for a function. QuickLogic's DSP Wizard software helps you configure the ECUs to implement various parameterizable cores, including generating the RAM-based coefficients for filters. The 0.25-µm QuickDSP family comprises four devices having 10 to 18 ECUs, 20 to 36 2304-bit RAM blocks, and 960 to 4032 programmable-logic blocks.
QuickDSP makes several other architecture improvements over the earlier pASIC3 and pASIC3-based QuickPCI families. Each I/O buffer now contains input, output, and output-enable registers and supports a variety of voltages, including differential standards, on a per-bank basis with eight I/O banks per chip. QuickLogic doubled the number of registers in each logic cell, added a multiplexer, and now provides as many as six outputs. You'll also find four PLLs and a beefed-up clock- and control-signal network. The parts are currently in design and are scheduled to be available for sampling by the end of the first quarter with the largest device to debut first, along with corresponding design-software support. Prices for Quick-DSPs begin at $19.95 (50,000) for the QL7100, and the company hopes to have the entire family available for sampling by the third quarter.
QuickLogic Corp, 1-408-990-4000, www.quicklogic.com.
-by Brian Dipert
