NXP Semiconductors MC7457RX867NC

Overview

MC7457RX867NC from Freescale Semiconductor is a 32-bit PowerPC G4 RISC microprocessor with 512-Kbyte on-chip L2 cache, 1.3 V core supply, and support for 1–4 MB external L3 SRAM via dedicated high-bandwidth interface. It integrates superscalar execution, AltiVec SIMD unit, dual MMUs, and hardware MESI coherency-targeted at high-performance networking and computing systems.

For engineers reviewing the MC7457RX867NC datasheet, MC7457RX867NC pinout, MC7457RX867NC application, or MC7457RX867NC equivalent, key selection considerations include its 483-ball CBGA package, 1.3 V ±50 mV core voltage, L3 interface configurability (1.5/1.8/2.5 V I/O), 9-cycle L1 data miss latency to L2, and footprint compatibility with MPC7455 in 1.3 V designs.

Technical Context

The MC7457RX867NC implements a seven-stage superscalar pipeline with three issue queues (FIQ/VIG/GIQ), supporting up to 16 simultaneous in-flight instructions and three instructions per cycle throughput. Its execution resources include four integer units, a five-stage IEEE 754-compliant FPU, and four vector units (VIU1/VIU2/VFPU/VPU) backed by 32-entry VR file and 16 rename buffers per register type.

Memory subsystem architecture features separate 32-Kbyte 8-way L1 instruction and data caches (Harvard), on-die 512-Kbyte unified L2 cache with 256-bit interface and PLRU replacement, and an L3 controller supporting 1–4 MB external SRAM with configurable cache/private memory split and 64-bit DDR/LW/PB2 synchronous burst SRAM interface.

Key Specifications

Pinout & Package

MC7457RX867NC is housed in a surface-mount 483-ball ceramic ball grid array (CBGA) package with thermal pad on underside. Ball pitch is 1.27 mm; package dimensions are 35 mm × 35 mm × 3.1 mm (height). Thermal pad must be soldered to internal ground plane for effective heat dissipation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MPC7455EC and MPC7447R, MC7457RX867NC offers higher L2 capacity (512 KB vs. 256 KB), full L3 interface support, and enhanced AltiVec throughput-making it optimal for bandwidth-intensive embedded computing where expandable cache and SIMD acceleration are critical.

Availability

MC7457RX867NC is available at Aetrix Electronics and suitable for networking infrastructure, industrial control systems, and telecom baseband equipment requiring stable component supply and long-term lifecycle support.

Supply support for MC7457RX867NC 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 MPC7457RX867NC belongs to Freescale's PowerPC G4 microprocessor family, designed specifically for high-throughput, low-latency embedded computing applications demanding integrated SIMD, scalable cache hierarchy, and robust multiprocessing support.

FAQ

What is the core supply voltage requirement for MC7457RX867NC?

The MC7457RX867NC requires a nominal 1.3 V core supply with tolerance of ±50 mV DC. This voltage must be delivered to all VDD pins with tight regulation and localized decoupling. Deviation beyond this range risks functional instability or permanent damage, as confirmed in Freescale's Hardware Specifications Rev. 7, Table 4. The MC7457RX867NC does not support dynamic voltage scaling - fixed 1.3 V operation is mandatory.

Does MC7457RX867NC support pin-compatible replacement for MPC7455 designs?

Yes - the MC7457RX867NC is a footprint-compatible, drop-in replacement for MPC7455 applications when the core power supply is 1.3 V. Both use the same 483-ball CBGA package and share identical pin assignments for core logic, MPX bus, and JTAG. However, MC7457RX867NC adds L3 interface pins (L3D[0:63], GVDD, L3VSEL) that must be properly terminated or configured; unused L3 signals should be pulled per Freescale's guidelines to avoid floating inputs.

What L3 SRAM configurations are supported by MC7457RX867NC?

The MC7457RX867NC supports 1 MB, 2 MB, or 4 MB total external SRAM space via its L3 interface. Up to 2 MB may be allocated as cache; the remainder (minimum 1 MB) can be configured as private memory. Supported SRAM types include MSUG2 DDR, PB2 pipelined, and late-write synchronous burst SRAMs. Line sizes are 64-byte (1 MB) or 128-byte (2 MB); 4 MB configuration uses 128-byte lines with half reserved for private memory.

How does the MC7457RX867NC handle thermal management?

The MC7457RX867NC implements thermal management through three supervisor-level registers and a dedicated thermal management exception. Software can throttle instruction fetching, enter Nap/Sleep/Deep Sleep modes, and monitor die temperature (0–105°C junction range). Its 20°C/W junction-to-ambient thermal resistance (RθJA) requires a thermally optimized PCB layout with exposed thermal pad soldered to ground plane and optional heatsink for sustained >1 GHz operation.

Is MC7457RX867NC compatible with 60x bus protocol?

The MC7457RX867NC supports a subset of the 60x bus protocol for main memory and system resource access, alongside its native MPX bus protocol. This partial compatibility enables integration into legacy 60x-based systems with appropriate glue logic or bridge ICs, but full 60x feature parity (e.g., certain cache coherency extensions) is not implemented. System designers must verify timing and signaling compliance using Freescale's MPX/60x interface specifications in Section 9 of the hardware manual.