NXP Semiconductors MPC745BPX350LE

Overview

MPC745BPX350LE from Freescale Semiconductor is a 350 MHz PowerPC™ RISC microprocessor implementing the 60x bus architecture, featuring a 32 KB instruction and 32 KB data L1 cache, full hardware branch prediction (512-entry BHT), and integrated thermal management assist unit (TAU) for junction temperature monitoring. It targets low-power embedded control and communications systems requiring deterministic real-time response and legacy PowerPC software compatibility.

For engineers reviewing the MPC745BPX350LE datasheet, MPC745BPX350LE pinout, MPC745BPX350LE application, or MPC745BPX350LE equivalent, key selection criteria include its lack of L2 cache interface (vs. MPC755), 255-ball PBGA package, 2.0 V core supply with 2.5/3.3 V I/O support, and support for doze/nap/sleep power states - all critical for thermal-constrained industrial and telecom edge platforms.

Technical Context

The MPC745BPX350LE implements the PowerPC Book III-E architecture with a dual-integer-unit (FXU1/FXU2), IEEE 754-compliant floating-point unit, and full out-of-order execution with six-entry reorder buffer and completion unit. Its memory subsystem includes 128-entry two-way set-associative TLBs and eight BATs per domain, supporting up to 4 GB physical memory and 4 exabytes virtual address space.

Unlike the MPC755, the MPC745BPX350LE omits the L2 cache controller, L2 tags, and L2 bus interface - eliminating external SRAM interfacing capability and reducing die size to 51 mm². It retains identical clock multiplier support (2×–10×), JTAG/COP debug interface, time base counter/decrementer, and performance monitor registers, ensuring functional parity in core execution and system control features.

Key Specifications

Pinout & Package

The MPC745BPX350LE is housed in a 255-ball plastic ball grid array (PBGA) package with 1.27 mm ball pitch, designed for standard reflow soldering and compatible with IPC-7351B footprint standards. Thermal pad on underside requires dedicated PCB copper pour for optimal heat dissipation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MPC755BX350LE, MPC745BPX350LE trades L2 cache support for lower power and smaller die area; compared with MPC8245LZQ350B, it lacks integrated PCI but delivers higher integer throughput per watt in standalone control applications.

Availability

MPC745BPX350LE is available at Aetrix Electronics and suitable for industrial automation, telecom infrastructure, avionics display systems, and medical imaging subsystems requiring stable component supply across extended product lifecycles.

Supply support for MPC745BPX350LE 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, analog, and connectivity solutions for automotive, industrial, and networking markets.

The MPC745BPX350LE belongs to Freescale's PowerPC 7xx family, designed specifically for cost-sensitive, thermally constrained embedded systems requiring binary compatibility with legacy PowerPC software and deterministic real-time performance.

FAQ

What is the maximum operating frequency of the MPC745BPX350LE?

The MPC745BPX350LE is rated for a maximum core frequency of 350 MHz, achieved via internal PLL multiplication of an external SYSCLK input (25–100 MHz). This frequency is guaranteed under recommended operating conditions: 1.90–2.10 V core supply, 2.375–2.625 V or 3.135–3.465 V I/O supply, and junction temperature ≤105°C. The device is sorted and tested to this speed grade during manufacturing.

Does the MPC745BPX350LE support L2 cache?

No, the MPC745BPX350LE does not support L2 cache. Unlike the MPC755, it omits the L2 cache controller, L2 tags, and L2 bus interface - a deliberate design distinction confirmed in Freescale's MPC755EC documentation. This reduces die size and power consumption but requires all data and instructions to reside in the 32 KB instruction and 32 KB data L1 caches or external memory.

What package type and ball count does the MPC745BPX350LE use?

The MPC745BPX350LE uses a 255-ball plastic ball grid array (PBGA) package with 1.27 mm ball pitch and 19 mm × 19 mm body size. This package is specified in Freescale's Electrical and Thermal Characteristics section and is distinct from the MPC755's optional 360-ball CBGA/PBGA variants. The 255-ball PBGA enables cost-effective assembly while delivering 34°C/W natural-convection thermal resistance.

How does the thermal management assist unit (TAU) function in the MPC745BPX350LE?

The MPC745BPX350LE integrates a thermal management assist unit (TAU) with an on-die temperature sensor, comparator, and dedicated SPRs (THRM0–THRM3). It provides raw thermal readings with ±12°C accuracy over 0–127°C, enabling software to trigger interrupts or initiate doze/nap modes before exceeding 105°C junction limit. Calibration and interpretation require firmware per Freescale Application Note AN1800/D.

What are the supported power management modes for the MPC745BPX350LE?

The MPC745BPX350LE supports three static power-saving modes: doze (core clock gated, buses active), nap (core clock stopped, buses retained), and sleep (full power-down with retention of critical registers). At 350 MHz, sleep mode draws ≤550 mW - verified in Table 7 of the MPC755EC datasheet, which explicitly states all information applies to MPC745 unless noted. Dynamic power management adjusts voltage/frequency based on workload.