NXP Semiconductors MPC850VR50BU

Overview

MPC850VR50BU from Freescale Semiconductor is a PowerQUICC™ integrated communications processor combining a 32-bit MPC8xx core with a dedicated RISC communications processor (CP), 8-Kbyte dual-port RAM, one Ethernet-capable serial communications controller (SCC), USB 1.1 host/slave controller, and PCMCIA-ATA interface - designed for cost-sensitive remote-access and telecom edge devices operating at up to 50 MHz.

For engineers reviewing the MPC850VR50BU datasheet, MPC850VR50BU pinout, MPC850VR50BU application, or MPC850VR50BU equivalent, this page delivers verified electrical specs (3.0–3.6 V operation), thermal resistance (θJA = 31 °C/W on multilayer board), bus timing (50 MHz max), CPM architecture details, and validated alternative parts for embedded networking hardware design.

Technical Context

The MPC850VR50BU implements a dual-processor architecture: a statically scheduled, single-issue MPC8xx core (PowerPC v.2.03) with 2-Kbyte I-cache and 1-Kbyte D-cache, plus an independent 32-bit Harvard-architecture communications processor (CP) executing microcode for protocol offload. The CP manages seven serial channels - including one SCC supporting IEEE 802.3 10-Mbps Ethernet, one USB 1.1 controller, two SMCs, one I²C port, and one SPI - using 8-Kbyte dual-port RAM and 20 SDMA channels.

Its system interface unit provides dynamic bus sizing (8/16/32-bit), IEEE 1149.1 JTAG debug, real-time clock, watchdog timer, and low-power modes (Doze, Sleep, Deep Sleep). Memory controller supports eight banks with glueless interfacing to SDRAM, SRAM, Flash, and EPROM, while the PCMCIA-ATA socket complies with JEIDA Release 2.1 and supports eight memory/I/O windows.

Key Specifications

Pinout & Package

Package: 352-ball PBGA (19 mm × 19 mm, 1.27 mm pitch), RoHS-compliant, lead-free.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MPC850DE and MPC850SR, the MPC850VR50BU offers optimal cost/performance for single-link remote access and edge routing - delivering full CPM offload and USB connectivity without paying for unused SCC or ATM features.

Availability

MPC850VR50BU is available at Aetrix Electronics and suitable for DSL modems, industrial gateways, remote access servers, and VoIP terminal adapters requiring stable component supply across extended product lifecycles.

Supply support for MPC850VR50BU 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 integrated communications processors, delivering high-reliability silicon for networking, telecom, and industrial control markets.

The MPC850 family - including MPC850VR50BU - was engineered for cost-sensitive, low-power embedded networking applications where protocol offload, peripheral integration, and long-term supply stability were critical design requirements.

FAQ

What is the maximum bus frequency supported by the MPC850VR50BU?

The MPC850VR50BU supports a maximum bus frequency of 50 MHz. When operated at higher core frequencies (e.g., 66 MHz or 80 MHz), it must be configured in half-speed bus mode - meaning the external bus runs at 33 MHz or 40 MHz respectively. This constraint is enforced by internal timing logic and documented in Table 6 of the MPC850EC Rev. 2 specification. The MPC850VR50BU datasheet confirms 50 MHz as the absolute bus speed limit under standard GPCM timing.

Does the MPC850VR50BU include an integrated Ethernet MAC?

Yes, the MPC850VR50BU integrates one Serial Communications Controller (SCC) with full IEEE 802.3-compliant 10-Mbps Ethernet MAC functionality, including preamble generation, CRC-32 calculation, and full-duplex collision detection. It does not include a PHY - external magnetics and a 10BASE-T PHY (e.g., DP83843) are required. The SCC supports both MII-like and simplified pinouts, and its operation is managed entirely by the CPM microcode, freeing the main MPC8xx core from frame-level processing.

What power supply configurations are required for the MPC850VR50BU?

The MPC850VR50BU requires four separate 3.3-V supply domains: VDDH (core logic), VDDL (I/O buffers), KAPWR (communications processor module), and VDDSYN (PLL circuitry). Each domain must be independently bypassed with ≥0.1 µF ceramic capacitors placed within 5 mm of the respective balls. DC specifications mandate 3.0–3.6 V at ≤40 MHz and tighter 3.135–3.465 V tolerance above 40 MHz. The MPC850VR50BU does not support internal voltage regulation or multi-voltage operation.

Is the MPC850VR50BU pin-compatible with other MPC850 variants?

Yes, the MPC850VR50BU is pin-compatible with all members of the MPC850 family packaged in the 352-ball PBGA (e.g., MPC850DE, MPC850SR, MPC850DSL), sharing identical mechanical footprint, ball map, and power/ground assignments. However, signal functionality differs: MPC850VR50BU exposes only one SCC, while MPC850DE exposes two, and MPC850SR adds UTOPIA pins. PCB layout may be reused, but firmware and schematic must account for variant-specific signal allocations.

What debugging interfaces does the MPC850VR50BU support?

The MPC850VR50BU supports IEEE 1149.1 (JTAG) boundary-scan testing and on-chip emulation via a dedicated test access port (TAP controller). It includes eight hardware watchpoint comparators - four for instruction address, two for data address, and two for data value - enabling precise breakpoint triggering on memory accesses or instruction execution. Debug capabilities are fully implemented in silicon and do not rely on external probes beyond standard JTAG adapters compatible with PowerPC v.2.03 architecture.