NXP Semiconductors MPC745BPX300LE

Overview

MPC745BPX300LE from Freescale Semiconductor is a 300 MHz PowerPC™ RISC microprocessor implementing the 60x bus architecture, featuring a 32 KB instruction and 32 KB data L1 cache, 0.22 µm CMOS process, 2.0 V core supply, and PBGA-255 packaging. It targets low-power embedded control and communications systems requiring deterministic real-time execution and thermal management support.

For engineers reviewing the MPC745BPX300LE datasheet, MPC745BPX300LE pinout, MPC745BPX300LE application, or MPC745BPX300LE equivalent, key selection considerations include its lack of L2 cache interface (vs. MPC755), 300 MHz core frequency with 25–100 MHz SYSCLK range, doze/nap/sleep power modes, thermal sensor integration, and 255-ball PBGA mechanical compatibility.

Technical Context

The MPC745BPX300LE implements the PowerPC instruction set with dual fixed-point units (FXU1/FXU2), a single-cycle latency floating-point unit supporting IEEE 754 single/double precision, and full hardware dependency detection in its dispatch unit. Its 64-entry branch target instruction cache (BTIC) and 512-entry branch history table (BHT) enable high prediction accuracy for deeply pipelined execution.

It integrates a memory management unit with 128-entry two-way set-associative instruction and data TLBs, eight instruction and eight data BATs, and supports up to 4 GB physical memory. The processor uses a 32-bit address bus and 64-bit data bus compatible with the 60x bus protocol, with bus-to-core multipliers ranging from 2× to 10×.

Key Specifications

Pinout & Package

Package: 255-ball plastic ball grid array (PBGA), surface-mount, 27 × 27 mm footprint, 1.27 mm ball pitch. Compatible with standard reflow profiles for lead-free assembly.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar RISC microprocessor applications.

Compared with MPC745BPX300LE, the MPC745BPX350LE offers higher clock rate with identical footprint and power delivery, while the MPC755EC adds L2 cache capability at the cost of mechanical and electrical redesign-making the former a direct upgrade path and the latter a system-level architectural change.

Availability

MPC745BPX300LE is available at Aetrix Electronics and suitable for telecom infrastructure, industrial automation, avionics, and medical imaging systems requiring stable component supply, long-lifecycle support, and qualified obsolescence management.

Supply support for MPC745BPX300LE 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

Freescale Semiconductor (now part of NXP Semiconductors) is a fabless semiconductor company specializing in embedded processing, connectivity, and analog solutions for automotive, industrial, and networking markets.

The MPC745 belongs to the PowerPC 7xx family designed for cost-sensitive, thermally constrained embedded applications where deterministic real-time performance and low static power outweigh raw compute density.

FAQ

What is the maximum operating frequency of the MPC745BPX300LE?

The MPC745BPX300LE is factory-sorted and guaranteed to operate at a maximum core frequency of 300 MHz. This is achieved using a 25–100 MHz SYSCLK input with a 3× PLL multiplier setting (PLL_CFG[0:3] = 0b0011). Operation above 300 MHz is not characterized or supported, and timing violations may occur.

Does the MPC745BPX300LE support L2 cache?

No, the MPC745BPX300LE does not implement the L2 cache interface. As explicitly stated in the Freescale documentation, it is identical to the MPC755 except for the omission of the internal L2 cache controller, tags, and L2 bus interface logic. External L2 SRAM cannot be connected via the MPC745BPX300LE's pinout.

What package type is used for the MPC745BPX300LE?

The MPC745BPX300LE uses a 255-ball plastic ball grid array (PBGA) package with a 27 × 27 mm body and 1.27 mm ball pitch. This is distinct from the MPC755, which was offered in both 360-ball CBGA and PBGA variants. The MPC745PBGA-only configuration ensures mechanical compatibility across all MPC745 speed grades.

How does the thermal management assist unit (TAU) function in the MPC745BPX300LE?

The MPC745BPX300LE integrates an on-die thermal sensor feeding a digital comparator and control logic. Raw output is read via THERM[0:3] pins and interpreted using the THRM3 special-purpose register. Software uses calibration data (per AN1800/D) to convert readings into junction temperature estimates with ±12°C accuracy, enabling proactive thermal throttling.

Can the MPC745BPX300LE operate with both 2.5 V and 3.3 V I/O interfaces simultaneously?

No - the MPC745BPX300LE supports either 2.5 V or 3.3 V I/O operation, selected at reset via the BVSEL pin. When BVSEL = 1, the device samples the OVDD supply voltage and configures input thresholds accordingly; it does not support mixed-voltage signaling on the same bus. Both voltages are allowed, but only one may be active per power cycle.