Texas Instruments TMS320C31PQL80

Overview

TMS320C31PQL80 from Texas Instruments is a 32-bit floating-point digital signal processor (DSP) operating at 5 V with 25-ns instruction cycle time, delivering 440 MOPS, 80 MFLOPS, and 40 MIPS. It integrates dual 1K × 32-bit on-chip RAM blocks, one serial port, two 32-bit timers, and a DMA coprocessor - deployed in real-time audio processing, radar baseband computation, and industrial motor control systems.

For engineers reviewing the TMS320C31PQL80 datasheet, TMS320C31PQL80 pinout, TMS320C31PQL80 application, or TMS320C31PQL80 equivalent, key selection considerations include its 132-pin PQ package, 5-V supply requirement, 24-bit address/32-bit data bus, dual-access RAM architecture, and support for zero-overhead loops and parallel ALU/multiplier execution.

Technical Context

The TMS320C31PQL80 implements a hardware-intensive DSP architecture with dedicated ARAUs, extended-precision registers (R0–R7), and interlocked instructions for multiprocessing. Its CPU executes two- and three-operand instructions in single cycles and supports block-repeat and conditional calls/returns.

It features a 0.6 µm EPIC CMOS process, 32-bit instruction word, and memory-mapped peripherals including serial port 0 (CLKX0/CLKR0/FSX0/FSR0/DX0/DR0), timer 0/1 (TCLK0/TCLK1), and interrupt inputs INT0–INT3. Bus control registers configure wait-state generation via STRB and RDY signals.

Key Specifications

Pinout & Package

132-pin plastic quad flat package (PQ), 27.0 × 27.0 mm body, 0.65 mm lead pitch, JEDEC MS-026 compliant. Thermal pad not present; no exposed die attach pad.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar floating-point DSP applications.

Compared with TMS320C32PQL80, the TMS320C31PQL80 lacks on-chip boot ROM and has fewer emulation pins, reducing debug visibility but lowering BOM cost. Against ADSP-21065L, it offers proven legacy toolchain support and lower power, but requires external memory for code storage and lacks native link-port inter-DSP communication.

Availability

TMS320C31PQL80 is available at Aetrix Electronics and suitable for industrial motor control, radar signal processing, audio DSP, and communications modem applications requiring stable component supply across long-lifecycle embedded programs.

Supply support for TMS320C31PQL80 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Texas Instruments is a U.S.-based semiconductor company founded in 1930, specializing in analog, embedded processing, and digital signal technologies with global manufacturing and design infrastructure.

The TMS320C3x product line was engineered for high-throughput, low-latency signal processing in resource-constrained embedded systems - emphasizing hardware acceleration of math-intensive operations over general-purpose flexibility.

FAQ

What is the maximum operating frequency supported by the TMS320C31PQL80?

The TMS320C31PQL80 operates with an 80-MHz internal clock derived from a 40-MHz external CLKIN signal (X2/CLKIN). Its 25-ns instruction cycle time corresponds to a sustained 40 MIPS execution rate. The device is rated for 5-V operation and achieves 80 MFLOPS under typical conditions at 25°C ambient temperature. The TMS320C31PQL80 does not support overclocking beyond its specified 40-MHz input clock limit.

Does the TMS320C31PQL80 support JTAG boundary-scan or IEEE 1149.1 debugging?

No, the TMS320C31PQL80 does not implement JTAG boundary-scan. It uses a proprietary four-wire emulation interface (EMU0–EMU3) for real-time debugging, with EMU3 as output and EMU0–EMU2 as inputs. These pins require pull-up resistors and are synchronized to internal clocks; they do not conform to IEEE 1149.1. Debugging relies on TI's XDS510-class emulators and Code Composer Studio v2.x toolchain.

Can the TMS320C31PQL80 execute code directly from external memory without boot-loading?

No, the TMS320C31PQL80 requires boot-loading into internal RAM before execution. It lacks on-chip flash or ROM; all program code must be loaded via microcomputer mode (serial EEPROM/host) or microprocessor mode (parallel bus). Execution begins at address 0x000000 after reset, which maps to internal RAM only after successful boot-load. External memory access is enabled post-boot using STRB/RDY-controlled wait states.

What are the power supply requirements and decoupling recommendations for the TMS320C31PQL80?

The TMS320C31PQL80 requires a clean 5-V ±2.5% supply (4.75–5.25 V) delivered to 20 VDD pins. Each VDD pin must be decoupled with a 0.1-µF ceramic capacitor placed within 5 mm of the pin and connected to the common ground plane. All 25 VSS pins must tie to a solid ground plane; split planes or star grounding is discouraged. Total typical supply current is 450 mA at 80 MHz operation, with peak transient currents managed by local capacitance.

How does the TMS320C31PQL80 handle external memory wait states?

The TMS320C31PQL80 inserts wait states using the RDY input and STRB output in conjunction with programmable bus-control registers. When RDY is low during a memory access, the processor extends the current cycle until RDY goes high. STRB remains active, and address/data remain valid. Wait-state count is controlled by the NOHOLD bit and STRB timing configuration - enabling compatibility with slow SRAM, EPROM, or peripheral devices without external glue logic.