NXP Semiconductors MPC855TCVR50D4R2

Overview

MPC855TCVR50D4R2 from Freescale Semiconductor is a PowerQUICC™ integrated communications controller combining a 32-bit Power Architecture™ CPU core and a RISC-based Communications Processor Module (CPM) in a single PBGA357 package. It delivers 50 MHz system clock operation, 4 KB instruction/4 KB data cache, IEEE 802.3-compliant 10/100 Mbps Ethernet support via SCC, and UTOPIA-level ATM interface for cell processing up to 70 Mbps - deployed in carrier-grade DSLAMs and enterprise edge routers.

For engineers reviewing the MPC855TCVR50D4R2 datasheet, MPC855TCVR50D4R2 pinout, MPC855TCVR50D4R2 application, or MPC855TCVR50D4R2 equivalent, this page provides verified technical context, validated pin functions, real-world timing constraints at 50 MHz bus speed, thermal resistance values for PCB layout planning, and two confirmed alternative parts with documented functional and packaging differences.

Technical Context

The MPC855TCVR50D4R2 implements a dual-core architecture: a 32-bit Power Architecture CPU with MMU, 4 KB instruction and 4 KB data caches, and a separate CPM executing communication-specific tasks including HDLC, UART, I²C, SPI, and FEC offload. Its memory controller supports eight banks with programmable wait states and glueless interfacing to DRAM, SRAM, Flash, and PCMCIA.

It integrates four Serial Communication Controllers (SCCs), two Serial Management Channels (SMCs), one I²C port, one SPI interface, and a Time-Slot Assigner (TSA) for TDM routing. The device operates at 3.3 V with 5-V-tolerant I/O (except EXTAL/EXTCLK), supports IEEE 1149.1 JTAG debug, and features low-power modes including Doze, Sleep, and Deep Sleep.

Key Specifications

Pinout & Package

Package: PBGA357 (ZQ/VR package code per Freescale case no. 5058, 25×25×1.2 mm, 1.27 mm ball pitch). Thermal pad on underside requires solder connection to ground plane for optimal heat dissipation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar integrated communications controller applications.

Compared with MPC860T, MPC855TCVR50D4R2 trades peak bandwidth for lower power (735 mW vs. 909 mW) and relaxed layout constraints; compared with MPC855T, it offers enhanced reliability screening and documented compatibility with newer Freescale reference designs.

Availability

MPC855TCVR50D4R2 is available at Aetrix Electronics and suitable for DSLAM line cards, enterprise edge routers, industrial protocol gateways, and TDM VoIP gateways requiring stable component supply across long-lifecycle deployments.

Supply support for MPC855TCVR50D4R2 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) was a pioneer in embedded communications processors, delivering high-integration SoCs for networking infrastructure from 1990s through 2010s.

The MPC855T family - including MPC855TCVR50D4R2 - was designed specifically for cost-sensitive, thermally constrained carrier and enterprise edge equipment requiring integrated Ethernet, ATM, and serial protocol acceleration without external co-processors.

FAQ

What is the maximum operating frequency of the MPC855TCVR50D4R2?

The MPC855TCVR50D4R2 is rated for a 50 MHz system clock frequency. Its bus interface operates at 50 MHz in 1:1 mode (CPU = bus speed), enabling full 10/100 Mbps Ethernet and UTOPIA ATM cell processing up to 70 Mbps. Higher-frequency variants like MPC860T support 66 MHz, but MPC855TCVR50D4R2 must not exceed 50 MHz per Freescale specification MPC855TUM Rev. 1.

Does the MPC855TCVR50D4R2 support IEEE 802.3u 100BASE-TX Ethernet?

Yes, the MPC855TCVR50D4R2 supports IEEE 802.3u 100BASE-TX Ethernet via its SCC1–SCC4 controllers when configured in MII mode. It requires an external PHY (e.g., DP83848) and uses dedicated pins including MII_MDC, MII_MDIO, MII_TXD[0:3], and MII_RXD[0:3]. Full-duplex 100 Mbps operation is validated at 50 MHz system clock per MPC855TUM Section 12.2.

What package type and thermal characteristics apply to the MPC855TCVR50D4R2?

The MPC855TCVR50D4R2 uses a 357-ball PBGA package (ZQ/VR package code, case no. 5058, 25×25×1.2 mm, 1.27 mm pitch). Its thermal resistance is RθJA = 34 °C/W (natural convection, single-layer board) and RθJB = 14 °C/W. The exposed thermal pad must be soldered to a solid ground plane for effective heat transfer - failure to do so risks junction temperature exceeding 95 °C at 735 mW dissipation.

Can the MPC855TCVR50D4R2 operate with 5-V logic inputs?

Yes, most I/O pins on the MPC855TCVR50D4R2 tolerate 5-V inputs (VIH up to 5.5 V), except EXTAL and EXTCLK which require VIHC = 0.7×VDDH to VDDH+0.3 V. However, all inputs must remain within 2.5 V above VDDH during power-up and operation - applying 5 V to unpowered MPC855TCVR50D4R2 risks latch-up or permanent damage per Table 2 Absolute Maximum Ratings.

What debugging interfaces does the MPC855TCVR50D4R2 provide?

The MPC855TCVR50D4R2 includes full IEEE 1149.1 (JTAG) test access port with TMS, TCK, TDI, TDO, and TRST pins. It also supports on-chip emulation with eight hardware watchpoint comparators (four instruction address, two data address, two data value) that generate internal breakpoints - enabling non-intrusive real-time tracing of CPU and CPM execution without halting the system.