NXP Semiconductors MPC855TZQ80D4

Overview

MPC855TZQ80D4 from Freescale Semiconductor is a PowerQUICC™ integrated communications controller combining a 32-bit Power Architecture™ CPU core, communications processor module (CPM), and system integration unit in a single PBGA357 package. It operates at up to 80 MHz, supports 10/100 Mbps Ethernet via SCCs, includes four serial communications controllers (SCCs), two serial management channels (SMCs), one SPI, one I²C port, and on-chip memory controller with eight banks for DRAM/SRAM/Flash. It targets embedded networking edge devices requiring deterministic real-time communication control.

For engineers reviewing the MPC855TZQ80D4 datasheet, MPC855TZQ80D4 pinout, MPC855TZQ80D4 application, or MPC855TZQ80D4 equivalent, key selection considerations include its 80-MHz CPU frequency, 4-KB instruction / 4-KB data cache configuration, IEEE 802.3u-compliant Ethernet support, UTOPIA-level ATM capability, and 357-pin PBGA package thermal and layout requirements.

Technical Context

The MPC855TZQ80D4 implements a dual-core architecture: a 32-bit Power Architecture™ CPU core with MMU, instruction/data caches, and branch prediction; and a RISC-based Communications Processor Module (CPM) handling protocol offload for HDLC, UART, IrDA, BISYNC, and ATM cell processing. Its CPM integrates 8 KB of dual-port RAM and 16 SDMA channels for autonomous peripheral data movement.

It features a programmable memory controller supporting dynamic bus sizing (8/16/32-bit), up to 15 wait states per bank, glueless interface to DRAM/SIMM/SRAM/Flash, and boot-selectable chip-enable width. The system integration unit provides clock synthesis, real-time clock, watchdog, IEEE 1149.1 JTAG debug, and low-power stop/doze/sleep modes - all operating from a 3.3-V supply with 5-V-tolerant I/O (except EXTAL/EXTCLK).

Key Specifications

Pinout & Package

Package: 357-ball plastic ball grid array (PBGA), ZQ package code (case no. 5058, 1103D-02), 25 mm × 25 mm footprint, 1.27-mm ball pitch, 1.2-mm height.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MPC860T, MPC855TZQ80D4 offers identical core functionality but fewer enabled SCCs and simplified ATM support, reducing cost and power for single-link edge applications; versus MPC855T, it guarantees 80-MHz operation in the ZQ package with documented D.4 silicon revision for production stability.

Availability

MPC855TZQ80D4 is available at Aetrix Electronics and suitable for DSL access multiplexers, industrial protocol gateways, secure remote terminal units, and legacy network bridges requiring stable component supply across extended product lifecycles.

Supply support for MPC855TZQ80D4 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) is a fabless semiconductor company specializing in embedded processing, connectivity, and analog solutions for automotive, industrial, and networking markets.

The MPC855T series belongs to the PowerQUICC™ family of integrated communications controllers, designed specifically for cost-sensitive, low-power embedded networking applications requiring real-time protocol offload and deterministic I/O handling.

FAQ

What is the maximum operating frequency of the MPC855TZQ80D4 CPU core?

The MPC855TZQ80D4 CPU core operates at a maximum frequency of 80 MHz. However, due to bus timing constraints, the external bus must run at 40 MHz in 2:1 mode (CPU:bus ratio). This configuration is explicitly validated in the hardware specifications for the D.4 die revision and is required to meet AC timing parameters such as CLKOUT-to-address valid (B8) and setup/hold windows.

Does the MPC855TZQ80D4 support IEEE 802.3u 100-Mbps Ethernet?

Yes, the MPC855TZQ80D4 supports IEEE 802.3u 10/100 Mbps Ethernet through its serial communications controllers (SCCs), specifically SCC1–SCC4. The hardware specification confirms full 100-Mbps operation capability when used with an external PHY via the MII interface (MII_MDC, MII_MDIO, MII_TXD[0:3], etc.), and compliance is contingent on proper PCB layout and signal integrity per Section 8 (Layout Practices).

What package type and pin count does the MPC855TZQ80D4 use?

The MPC855TZQ80D4 uses a 357-ball plastic ball grid array (PBGA) package with ZQ package code (case no. 5058, 1103D-02), measuring 25 mm × 25 mm with 1.27-mm ball pitch. This matches the mechanical data in Table 3 of the MPC860 Hardware Specifications and is distinct from the ZP variant (1.0-mm height).

Can the MPC855TZQ80D4 operate with a 5-V external clock input?

No, the MPC855TZQ80D4 EXTAL and EXTCLK inputs are not 5-V tolerant. Per Table 6, VIHC (input high voltage for EXTAL/EXTCLK) is specified as 0.7 × VDDH to VDDH + 0.3 V. With VDDH = 3.3 V, this limits EXTCLK to a maximum of 3.6 V. Applying 5 V risks permanent damage and violates absolute maximum ratings in Table 2.

What is the cache configuration of the MPC855TZQ80D4?

The MPC855TZQ80D4 implements a 4-KB instruction cache (2-way set-associative, 128 sets) and a 4-KB data cache (2-way set-associative, 128 sets), as confirmed in Table 1 and Section 2 (Features) of the MPC860 Hardware Specifications. Cache coherency is maintained on 128-bit blocks, and both caches are physically addressed with LRU replacement and lockable blocks.