NXP Semiconductors MPC850DSLZQ50BU

Overview

MPC850DSLZQ50BU from Freescale Semiconductor is a PowerQUICC™ integrated communications processor featuring a 32-bit MPC8xx core, dual serial communications controllers (SCCs), Ethernet/IEEE 802.3 support, ATM capability, and 8-Kbyte dual-port RAM. It operates at up to 50 MHz with 3.3-V core logic and 5-V-tolerant I/O, targeting cost-sensitive remote-access and telecommunications infrastructure.

For engineers reviewing the MPC850DSLZQ50BU datasheet, MPC850DSLZQ50BU pinout, MPC850DSLZQ50BU application, or MPC850DSLZQ50BU equivalent, this page delivers verified electrical specs, bus timing constraints at 50 MHz, CPM architecture details, thermal resistance (θJA = 31 °C/W), and confirmed USB/SCC/I²C/SMC peripheral integration - all specific to the MPC850DSL variant.

Technical Context

The MPC850DSLZQ50BU implements a dual-processor architecture: a main MPC8xx core handling system control and a dedicated 32-bit RISC communications processor (CP) within the CPM that offloads serial protocol processing. Its CPM supports two SCCs (Ethernet + ATM), two SMCs, one I²C port, one SPI, and one USB controller - all sharing 8-Kbyte dual-port RAM and 20 SDMA channels.

It uses a Harvard-cache architecture (2-Kbyte instruction cache, 1-Kbyte data cache), MMUs with 8-entry TLBs, and dynamic bus sizing for 8/16/32-bit memory interfaces. The SIU provides IEEE 1149.1 JTAG debug, real-time clock, watchdog, and low-power stop/sleep/deep-sleep modes - all validated for the MPC850DSL family revision.

Key Specifications

Pinout & Package

Package: 324-pin PBGA (27 mm × 27 mm, 1.27 mm ball pitch), RoHS-compliant, lead-free finish. Thermal pad on underside requires solder paste stencil opening per Freescale AN-1231/D guidelines.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MPC850SRZQ50B and MPC850DEZQ50B, the MPC850DSLZQ50BU uniquely balances ATM + Ethernet + USB in a single 50 MHz device - making it optimal for hybrid DSL/ATM/Ethernet edge nodes where protocol flexibility and field-upgradability via USB are required.

Availability

MPC850DSLZQ50BU is available at Aetrix Electronics and suitable for DSLAM line cards, industrial RTUs, VoIP gateways, telecom signaling processors, and embedded networking appliances requiring stable component supply across extended product lifecycles.

Supply support for MPC850DSLZQ50BU 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 embedded networking, emphasizing hardware-accelerated protocol offload and deterministic real-time performance.

The MPC850DSLZQ50BU belongs to the MPC850 PowerQUICC™ family, designed specifically for cost-sensitive, remote-access, and telecommunications infrastructure requiring integrated Ethernet, ATM, and serial protocol handling in a single-chip solution.

FAQ

What is the maximum bus speed supported by the MPC850DSLZQ50BU?

The MPC850DSLZQ50BU supports a maximum bus speed 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 a 66 MHz core requires a 33 MHz bus clock. This constraint is enforced by internal timing logic and verified in Table 6 of the MPC850EC Rev. 2 specification. Bus timing parameters for 50 MHz operation are fully characterized, including setup/hold windows for address, data, and control signals relative to CLKOUT.

Does the MPC850DSLZQ50BU support both ATM and Ethernet simultaneously?

Yes, the MPC850DSLZQ50BU supports concurrent ATM and Ethernet operation. Its two serial communications controllers (SCCs) are independently configurable: one can run ATM over TDM (per MPC850DSL functionality matrix), while the other handles full-duplex 10-Mbps Ethernet/IEEE 802.3. The CPM's time slot assigner and dual-port RAM enable synchronized data movement between protocols without CPU intervention - a capability confirmed in Freescale's MPC850 Family Hardware Specifications Rev. 2.

What package type and thermal characteristics apply to the MPC850DSLZQ50BU?

The MPC850DSLZQ50BU uses a 324-pin PBGA package (27 mm × 27 mm, 1.27 mm pitch) with a thermal resistance θJA of 31 °C/W under natural convection on a multilayer board with thermal vias and 1 W power dissipation. Junction temperature is rated from –40°C to 95°C (extended temperature grade). These values are specified in Tables 3 and 4 of the MPC850EC Rev. 2 document and apply identically to all MPC850DSL variants, including MPC850DSLZQ50BU.

How does the CPM in the MPC850DSLZQ50BU reduce CPU load for serial protocols?

The CPM in the MPC850DSLZQ50BU contains a dedicated 32-bit RISC communications processor (CP) that executes protocol-specific microcode for Ethernet, ATM, HDLC, and USB - freeing the main MPC8xx core from bit-level framing, CRC generation, and buffer management. For example, the CP supports GRACEFUL STOP TRANSMIT and CLOSE RXBD commands, enabling safe frame completion and receive buffer closure without software polling. This architecture reduces CPU utilization by up to 70% for high-throughput serial traffic, as documented in the MPC850 PowerQUICC™ Hardware Specifications Rev. 2.

Is USB functionality available on the MPC850DSLZQ50BU, and what modes does it support?

Yes, the MPC850DSLZQ50BU includes a full-speed USB 1.1 controller supporting both host and slave (device) modes at 1.5 Mbps and 12 Mbps. Unlike the MPC850SR, the MPC850DSL retains USB support while adding ATM capability - a key differentiator per Table 1 of the MPC850 Family Functionality Matrix. USB endpoints are serviced by eight dedicated serial DMA channels within the CPM, enabling zero-CPU-intervention data transfers during firmware updates or peripheral attachment.