NXP Semiconductors KMC7457VG1000NC

Overview

KMC7457VG1000NC from Freescale Semiconductor is a 1.3 V core, 1 GHz PowerPC G4 RISC microprocessor with integrated 512-Kbyte unified L2 cache, on-die L3 cache controller supporting up to 4-MB external SRAM, and AltiVec™ vector processing unit. It implements full 32-bit PowerPC architecture and targets high-performance networking and computing systems requiring glueless L3 expansion and IEEE 754-1985-compliant double-precision floating-point execution.

For engineers reviewing the KMC7457VG1000NC datasheet, KMC7457VG1000NC pinout, KMC7457VG1000NC application, or KMC7457VG1000NC equivalent, this page delivers verified electrical specs (1.3 V ±50 mV core, 1.5/1.8/2.5 V I/O options), thermal resistance (RθJA = 20°C/W), L2/L3 cache interface timing, superscalar dispatch throughput (3 instructions/cycle), and confirmed MPC7457-specific features including BTIC/BHT branch prediction and MPX bus protocol support.

Technical Context

The KMC7457VG1000NC implements a seven-stage superscalar pipeline with three independent issue queues (FIQ, VIQ, GIQ) enabling up to three instructions dispatched per cycle. Its execution resources include four integer units, five-stage IEEE 754-1985-compliant FPU, and four AltiVec units (VIU1, VIU2, VFPU, VPU) operating on a 32-entry vector register file.

Memory subsystem architecture integrates separate instruction and data MMUs with 128-entry two-way set associative TLBs, 32-Kbyte eight-way L1 caches (physically indexed), and an on-chip 512-Kbyte eight-way unified L2 cache delivering 32 bytes/cycle to L1. The dedicated L3 interface supports 64-bit DDR synchronous burst SRAMs with configurable 1/2/4-MB total space and private memory partitioning.

Key Specifications

Pinout & Package

Package: Surface-mount 483-ball ceramic ball grid array (CBGA), 35 mm × 35 mm, 1.27 mm pitch, RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MPC7455EC and MPC7447V, KMC7457VG1000NC provides 100% higher L2 cache bandwidth and unique L3 controller logic-enabling scalable memory architectures impossible on alternatives-while maintaining pin compatibility with both for board reuse in upgrade paths.

Availability

KMC7457VG1000NC is available at Aetrix Electronics and suitable for network infrastructure, scientific computing, industrial automation, and digital signal processing applications requiring stable component supply across extended product lifecycles.

Supply support for KMC7457VG1000NC 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 processors, analog, and connectivity solutions for automotive, industrial, and networking markets.

The MPC7457 product line was designed as the fourth-generation PowerPC G4 microprocessor targeting high-throughput computing systems requiring AltiVec acceleration, low-latency cache hierarchies, and scalable L3 memory expansion-specifically for telecom infrastructure and workstation applications.

FAQ

What is the maximum operating frequency of the KMC7457VG1000NC?

The KMC7457VG1000NC operates at a fixed 1.0 GHz frequency. This speed is guaranteed under recommended conditions: 1.3 V ±50 mV core supply, junction temperature ≤105°C, and proper SYSCLK signal integrity. The part does not support dynamic frequency scaling; its PLL locks to generate a stable 1 GHz output from the input reference clock. All timing specifications-including L1 miss latency and instruction dispatch rates-are validated at this frequency.

Does the KMC7457VG1000NC support 2.5 V I/O interfaces?

Yes, the KMC7457VG1000NC supports 2.5 V I/O on both the processor bus and L3 interface. For the processor bus, setting BVSEL to HRESET or OVDD configures OVDD pins for 2.5 V ±5%. For the L3 bus, setting L3VSEL to HRESET or GVDD enables GVDD pins at 2.5 V ±5%. These selections are latched at HRESET negation and must match the actual supply voltages applied to avoid input threshold violations.

How much L3 cache memory can be implemented with the KMC7457VG1000NC?

The KMC7457VG1000NC supports up to 4 MB of external SRAM via its L3 interface, but only up to 2 MB may be configured as cache memory. The remaining capacity (minimum 1 MB, up to 2 MB) must be allocated as private memory. Supported SRAM types include MSUG2 DDR, PB2 pipelined, and late-write synchronous burst devices, all accessed through a 64-bit data path with configurable core-to-L3 frequency divisors.

Is the KMC7457VG1000NC pin-compatible with earlier MPC745x processors?

The KMC7457VG1000NC uses a 483-ball CBGA package identical to the MPC7455EC, enabling direct PCB footprint reuse. However, it is not pin-compatible with the MPC7447 (which uses a 360-ball CBGA) or MPC7450 series (256-ball CBGA). Electrical compatibility requires matching 1.3 V core supply and verifying BVSEL/L3VSEL configuration against target I/O voltage levels.

What thermal management features does the KMC7457VG1000NC include?

The KMC7457VG1000NC includes three hardware power-saving modes (Nap, Sleep, Deep Sleep), instruction cache throttling, and a thermal management exception triggered by supervisor-level registers. These features allow software to dynamically reduce power consumption during idle periods or high-temperature events. The part's RθJA of 20°C/W requires active cooling for sustained 1 GHz operation above 65°C ambient, and thermal sensors must be calibrated per Section 9.8 of the hardware specification.