EDN — 01.18.96 Low-cost, 64-bit MIPS µP supports DSP operations

Out in Front: January 18, 1996

Low-cost, 64-bit MIPS µP supports DSP operations

Integrated Device Technology’s (IDT’s) Orion R4640 µP gives you 64-bit processing power and 175 Dhrystone MIPS for $28. An R4650 derivative, the R4640 contains a five-stage pipeline and a single-precision floating-point coprocessor that decodes and executes instructions in parallel with the integer unit. Although the R4640 implements the MIPS-III instruction set, it also supports math instructions for DSP operations.

The R4640’s dedicated integer multiply/divide unit supports the DSP operations with an atomic multiply-add instruction. The integer unit also handles a new multiply instruction that specifies that multiply results bypass the Lo register and go immediately to the primary register file. The R4640 automatically detects operand size and implements hardware interlocks to prevent overrun.

Two-way, set-associative, 8-kbyte instruction and data caches have write-back and -through capability. The R4640’s caches also support cache locking to benefit real-time operation. In addition to being a static core, the R4640 has active power-down modes: The µP consumes less than 200 mW in standby mode.

To reduce system cost and help limit pin count to 128, the R4640 has a 32-bit system interface. The devices come in 5 and 3.3V versions in 128-pin MQUADs and 128-pin PQFPs, respectively. Prices for the 5 and 3.3V versions start at $32 and $28, respectively (10,000). Device operating frequencies are 80, 100, and 133 MHz.

IDT also provides development tools to support the R4640. These tools include development/evaluation boards, software tools, bus models, logic-analyzer support, and real-time operating-system (pSOSystem and Wind River VxWorks) support. — by Markus Levy

Integrated Device Technology,
Santa Clara, CA. (800) 345-7015.