NXP Semiconductors MPC850DECVR66BU

Overview

MPC850DECVR66BU from Freescale Semiconductor is a PowerQUICC™ integrated communications processor combining an embedded 32-bit MPC8xx core with a dedicated RISC communications processor (CP), dual-port RAM (8 KB), Ethernet MAC, USB 1.1 controller, two SCCs, two SMCs, SPI, I²C, and PCMCIA-ATA interface - designed for cost-sensitive remote-access and telecom edge devices operating at up to 66 MHz core frequency.

For engineers reviewing the MPC850DECVR66BU datasheet, MPC850DECVR66BU pinout, MPC850DECVR66BU application, or MPC850DECVR66BU equivalent, key selection considerations include its dual-SCC Ethernet/HDLC support, USB host/slave capability, 3.3-V operation with 5-V-tolerant I/O, BGA-352 package, and requirement for half-speed bus configuration (33 MHz) when running at 66 MHz core clock.

Technical Context

The MPC850DECVR66BU implements a split-processor architecture: the main MPC8xx core handles system control and application tasks, while the independent 32-bit Harvard-architecture communications processor (CP) offloads serial protocol processing (Ethernet, HDLC, USB, UART, SPI, I²C) using 8 KB of on-chip dual-port RAM and 20 SDMA channels. It supports IEEE 802.3 10-Mbps Ethernet via SCC1/SCC2 and full-duplex USB 1.1 at 1.5/12 Mbps.

Its memory subsystem includes an eight-bank programmable controller supporting SDRAM, SRAM, Flash, and EPROM with boot-selectable 8/16/32-bit interfaces; bus timing requires external configuration via UPM (User Programmable Machine) microcode, and the device mandates half-speed bus operation (33 MHz) when the core runs at 66 MHz - confirmed in Table 6 timing specifications for 66 MHz mode.

Key Specifications

Pinout & Package

Package: 352-ball PBGA (Plastic Ball Grid Array), 27 mm × 27 mm, 1.27 mm pitch, RoHS-compliant. Thermal pad on underside requires soldered thermal connection to internal ground plane.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MPC850DECVR66BU, MPC850DEVR66B offers identical functionality with mechanical rework needed, while MPC860TVR66D trades USB/PCMCIA for higher CPM bandwidth and no USB - making it optimal for pure telecom line cards but incompatible with USB-dependent field service workflows.

Availability

MPC850DECVR66BU is available at Aetrix Electronics and suitable for DSLAM line cards, industrial Ethernet gateways, remote terminal units (RTUs), VoIP adapters, and SCADA edge controllers requiring stable component supply across extended product lifecycles.

Supply support for MPC850DECVR66BU 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 since 2015) was a pioneer in PowerPC-based communications processors, delivering high-integration SoCs for networking and telecom infrastructure.

The MPC850 family was engineered specifically for cost-sensitive, low-power remote access and telecommunications edge devices - integrating Ethernet, USB, HDLC, and PCMCIA into a single chip to replace multi-chip controller solutions.

FAQ

What is the maximum supported bus speed for MPC850DECVR66BU at 66 MHz core frequency?

The MPC850DECVR66BU must operate in half-speed bus mode when the core runs at 66 MHz, limiting the external bus clock to 33 MHz. This is explicitly mandated in Section 6 ("Bus Signal Timing") of the hardware specifications - Table 6 lists timing parameters only for 50/66/80 MHz core speeds with corresponding 25/33/40 MHz bus rates. Attempting full-speed 66 MHz bus operation violates setup/hold timing (e.g., B18–B21) and risks data corruption.

Does MPC850DECVR66BU support USB 2.0?

No, MPC850DECVR66BU integrates a USB 1.1 controller compliant with USB Specification Revision 1.1, supporting only low-speed (1.5 Mbps) and full-speed (12 Mbps) modes. It does not implement USB 2.0 high-speed (480 Mbps) transceivers, PHY, or protocol engine - confirmed by absence of UTMI+ interface signals and USB 2.0 descriptors in all documentation, including the MPC850EC Rev. 2 datasheet.

How is Ethernet connectivity implemented on MPC850DECVR66BU?

MPC850DECVR66BU implements Ethernet at the MAC layer via two Serial Communications Controllers (SCCs), each supporting IEEE 802.3 10-Mbps baseband operation. It requires external PHY devices (e.g., DP83843 or LAN83C185) and magnetics for physical layer connectivity. The SCCs handle frame assembly/disassembly, CRC generation/checking, and MII/RMII signaling - no integrated PHY is present on-die.

What power supply sequencing is required for MPC850DECVR66BU?

MPC850DECVR66BU requires simultaneous ramp-up of all four power domains (VDDH, VDDL, KAPWR, VDDSYN) within ±100 ms of each other, with no voltage exceeding another by more than 0.3 V during startup. Asymmetric sequencing or >0.3 V differentials between supplies may cause latch-up or undefined reset behavior - specified in Section 5 ("Power Considerations") and reinforced by absolute maximum ratings in Table 2.

Is MPC850DECVR66BU pin-compatible with MPC850SR or MPC850DSL variants?

No, MPC850DECVR66BU is not pin-compatible with MPC850SR or MPC850DSL. While all share the BGA-352 package, Table 1 ("MPC850 Functionality Matrix") confirms differing peripheral configurations: MPC850DECVR66BU has two SCCs and USB support but no ATM capability, whereas MPC850SR/DSL add UTOPIA ports and ATM support - requiring distinct pin allocations for UTOPIA signals (TxDAT, RxDAT, etc.) absent in MPC850DECVR66BU's signal list.