NXP Semiconductors MC7457RX1267LC

Overview

MC7457RX1267LC from Freescale Semiconductor is a 1.3 V core, 512-Kbyte on-chip L2 cache, PowerPC G4 RISC microprocessor with integrated L3 cache controller, AltiVec™ SIMD unit, and MPX/60x bus interface. It delivers up to three instructions per cycle throughput in networking and embedded computing systems requiring high floating-point and vector processing performance.

For engineers reviewing the MC7457RX1267LC datasheet, MC7457RX1267LC pinout, MC7457RX1267LC application, or MC7457RX1267LC equivalent, key selection criteria include its 1.3 V core supply, 483-ball CBGA package, L3 SRAM interface supporting 1–4 MB external SRAM, 32-Kbyte L1 instruction/data caches, and thermal management modes (Nap/Sleep/Deep Sleep).

Technical Context

The MC7457RX1267LC implements a seven-stage superscalar pipeline with four integer units, five-stage IEEE 754-1985 compliant FPU, and four AltiVec execution units (VIU1, VIU2, VFPU, VPU). Its memory subsystem features dual MMUs with 128-entry two-way TLBs, hardware-enforced MESI coherency, and support for 32-bit virtual/36-bit physical addressing.

It integrates an on-die 512-Kbyte unified L2 cache with 64-byte two-sectored lines and parity protection, plus an L3 cache controller supporting MSUG2 DDR, PB2, and late-write synchronous burst SRAMs via a 64-bit external data bus. Core-to-L3 frequency divisors are configurable, and private memory allocation is supported for half or all of the L3 SRAM space.

Key Specifications

Pinout & Package

MC7457RX1267LC is housed in a surface-mount 483-ball ceramic ball grid array (CBGA) package with 1.27 mm pitch, designed for high-density PCB layouts and thermal reliability in industrial computing applications.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MPC7455EC and MPC7447EC, MC7457RX1267LC uniquely supports 1–4 MB external L3 SRAM with private memory partitioning, enabling scalable cache hierarchies in high-performance embedded systems where MPC7455EC's 256-Kbyte L2 and MPC7447EC's lack of L3 interface impose hard capacity limits.

Availability

MC7457RX1267LC is available at Aetrix Electronics and suitable for networking equipment, embedded computing platforms, and industrial control systems requiring stable component supply and long-term lifecycle support.

Supply support for MC7457RX1267LC 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 was a leading designer of embedded processors, analog, and connectivity solutions before its acquisition by NXP Semiconductors in 2015.

The MPC7457 product line delivers high-performance PowerPC G4 microprocessors optimized for compute-intensive embedded applications including telecom infrastructure, test equipment, and real-time control systems.

FAQ

What is the core supply voltage requirement for MC7457RX1267LC?

The MC7457RX1267LC requires a nominal 1.3 V ±50 mV DC core supply (VDD) for stable operation. This voltage must be maintained within tolerance across all operating conditions, including transient load changes. The MC7457RX1267LC datasheet specifies that VDD must not exceed OVDD or GVDD by more than 1.0 V during normal operation, and this margin may be exceeded for up to 20 ms only during power-on reset or power-down sequences.

Does MC7457RX1267LC support L3 cache expansion, and what SRAM types are compatible?

Yes, MC7457RX1267LC integrates an L3 cache controller supporting 1 MB, 2 MB, or 4 MB total external SRAM space via a 64-bit data bus. It is compatible with MSUG2 DDR synchronous burst SRAMs, PB2 pipelined synchronous burst SRAMs, and pipelined late-write synchronous burst SRAMs. The MC7457RX1267LC allows configuration of up to 2 MB as cache space, with the remainder usable as private memory.

What package type and pin count does MC7457RX1267LC use?

MC7457RX1267LC uses a 483-ball ceramic ball grid array (CBGA) package with 1.27 mm pitch. This package is footprint-compatible with the MPC7455EC, enabling drop-in replacement in existing 1.3 V core designs. The MC7457RX1267LC pinout includes dedicated VDD, OVDD, and GVDD power balls, along with MPX bus signals, SYSCLK, HRESET, and JTAG interface pins.

How does MC7457RX1267LC handle thermal management in embedded systems?

MC7457RX1267LC implements three hardware-supported power-saving modes: Nap (halts instruction fetch while maintaining time base and JTAG), Sleep (disables bus snooping, retains PLL lock), and Deep Sleep (disables PLL and SYSCLK). Thermal management is controlled via three supervisor-level registers and a dedicated thermal management exception, allowing software to throttle instruction fetching or trigger transitions between states based on die-junction temperature readings.

Is MC7457RX1267LC pin-compatible with MPC7447EC, and what are the key functional differences?

No, MC7457RX1267LC is not pin-compatible with MPC7447EC. While both share the PowerPC G4 core and 512-Kbyte L2 cache, MC7457RX1267LC includes GVDD power pins and L3 interface signals absent on MPC7447EC's 360-ball CBGA package. The MC7457RX1267LC also supports 1.5 V L3 I/O operation, whereas MPC7447EC lacks L3 functionality entirely. These differences prevent direct substitution without PCB redesign.