NXP Semiconductors MPC850SRVR50BU

Overview

MPC850SRVR50BU from Freescale Semiconductor is a PowerQUICC™ integrated communications processor featuring a 32-bit MPC8xx core, dual-port RAM (8 KB), two serial communications controllers (SCCs) with Ethernet/IEEE 802.3 support, USB 1.1 host/slave controller, and a dedicated RISC communications processor (CP). It targets cost-sensitive remote-access and telecommunications equipment requiring deterministic serial protocol handling and low-power operation.

For engineers reviewing the MPC850SRVR50BU datasheet, MPC850SRVR50BU pinout, MPC850SRVR50BU application, or MPC850SRVR50BU equivalent, this page delivers verified electrical specs (3.3 V operation, 50 MHz bus), thermal data (θJA = 31 °C/W), CPM architecture details, and confirmed functional differentiation within the MPC850 family - specifically its dual-SCC + ATM + USB configuration.

Technical Context

The MPC850SRVR50BU implements a Harvard-architecture embedded MPC8xx core (2 KB I-cache, 1 KB D-cache) tightly coupled to a separate 32-bit RISC communications processor (CP) that offloads serial protocol processing. Its CPM supports up to seven serial channels: two SCCs (Ethernet/HDLC/ATM), one USB, two SMCs, one I²C, and one SPI - all managed via 20 SDMA channels and four baud-rate generators.

It integrates a programmable memory controller (eight banks, DRAM/SDRAM/SRAM/Flash support), IEEE 1149.1 JTAG debug interface, real-time clock, PCMCIA-ATA socket, and time-slot assigner for TDM multiplexing. Power management includes five modes (Full High, Full Low, Doze, Sleep, Deep Sleep), with dynamic voltage scaling between 2.2 V (≤25 MHz) and 3.3 V (≥40 MHz).

Key Specifications

Pinout & Package

Package: 352-ball PBGA (Plastic Ball Grid Array), 27 mm × 27 mm, 1.27 mm pitch, RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MPC850DEVR50BU and MPC850DSLVR50BU, the MPC850SRVR50BU uniquely combines dual-SCC Ethernet/ATM capability *and* USB 1.1 - enabling hybrid access devices (e.g., DSL+USB printer server) where the alternatives require external USB controllers or omit ATM entirely.

Availability

MPC850SRVR50BU is available at Aetrix Electronics and suitable for DSL access concentrators, enterprise VoIP gateways, remote terminal units, and industrial protocol converters requiring stable component supply and long-term lifecycle support.

Supply support for MPC850SRVR50BU 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) pioneered PowerQUICC™ communications processors for networking and telecom infrastructure.

The MPC850 family was designed to integrate CPU, memory controller, and protocol-aware communications processing onto a single die - targeting cost-sensitive, high-volume remote-access and DSL equipment where software-defined flexibility meets hardware acceleration.

FAQ

What is the maximum supported bus speed for the MPC850SRVR50BU?

The MPC850SRVR50BU supports a maximum bus speed of 50 MHz. When operated at higher CPU frequencies (e.g., 66 MHz or 80 MHz), it must be configured in half-speed bus mode - meaning a 66 MHz CPU runs with a 33 MHz bus clock. This constraint is enforced by internal timing logic and documented in Table 6 of the hardware specifications. The MPC850SRVR50BU does not support full-speed 66 MHz or 80 MHz bus operation.

Does the MPC850SRVR50BU include built-in Ethernet PHY functionality?

No, the MPC850SRVR50BU does not include an integrated Ethernet PHY. It provides two SCCs with MII/RMII-compatible digital interfaces (TXD/RXD, TX_EN, CRS, COL, etc.) that require an external 10BASE-T or 10/100BASE-TX PHY IC (e.g., DP83848) and appropriate magnetics. The MPC850SRVR50BU handles MAC-layer framing, CRC, and protocol processing; physical layer signaling is external.

How does the MPC850SRVR50BU differ from the MPC850SR in terms of package and thermal performance?

The MPC850SRVR50BU is the 352-ball PBGA variant rated for 50 MHz operation with validated thermal resistance θJA = 31 °C/W (multilayer board with thermal vias). It replaces earlier ceramic PGA or QFP packages. The "VR" suffix denotes this specific PBGA packaging and revision, while "50BU" confirms the 50 MHz speed grade and commercial temperature range (0–95 °C junction). Thermal design must follow AN-1231/D layout guidelines.

Can the MPC850SRVR50BU operate in low-power modes while maintaining Ethernet link status?

Yes - in Doze mode, the MPC850SRVR50BU keeps the memory controller, real-time clock, PLL, and CPM active while disabling the main MPC8xx core. Since the CPM handles Ethernet packet processing independently, link-layer keep-alives and auto-negotiation can continue uninterrupted. However, full Sleep and Deep Sleep modes disable the CPM and require external PHY wake-on-LAN or RTC-triggered wake-up to restore connectivity.

What debugging interfaces are supported by the MPC850SRVR50BU?

The MPC850SRVR50BU includes IEEE 1149.1 (JTAG) test access port with boundary-scan support, plus an advanced on-chip emulation debug mode with eight hardware comparators (four instruction address, two data address, two data value). It supports watchpoint-triggered breakpoints and real-time trace via the BDM (Background Debug Mode) interface - accessible through standard Freescale BDM debug probes compatible with the MPC8xx architecture.