NXP Semiconductors MPC875ZT66

Overview

MPC875ZT66 from Freescale Semiconductor is a PowerQUICC™ integrated communications processor combining a 32-bit MPC8xx core, dual Fast Ethernet controllers (FEC), USB 2.0 host/function interface, security engine (AES/DES/SHA), and CPM-based serial peripherals - all in a single 256-pin PBGA package operating at 66 MHz core/bus (1:1 mode). It targets ATM edge routers, secure VPN gateways, and industrial Ethernet controllers requiring deterministic real-time packet processing.

For engineers reviewing the MPC875ZT66 datasheet, MPC875ZT66 pinout, MPC875ZT66 application, or MPC875ZT66 equivalent, this page delivers verified specifications including 1.8-V core / 3.3-V I/O operation, 8-KB instruction + 8-KB data caches, IEEE 802.3 10/100 Mbps FECs, hardware-accelerated IPsec/SSL crypto, and mandatory reset configuration requirements for boot stability.

Technical Context

The MPC875ZT66 implements a single-issue Power Architecture™ core with MMU, two-way set-associative caches (8 KB each), and 32-entry TLBs supporting 4/16/512 KB and 8 MB page sizes. Its system integration unit (SIU) provides clock synthesis, JTAG debug, PIT, and software watchdog - all synchronized to the 66 MHz bus frequency.

Communications are handled by a dedicated RISC-based CPM with 8 KB dual-port RAM, four baud-rate generators, three SCCs (including HDLC/UART/IrDA), one SMC, and a time-slot assigner (TSA) for TDM multiplexing. The security engine integrates AESU (128/192/256-bit), DEU (DES/3DES), and MDEU (SHA-1/256, MD5) with DMA-controlled crypto-channel descriptors.

Key Specifications

Pinout & Package

Package: 256-ball PBGA (17 mm × 17 mm, 1.0 mm pitch), RoHS-compliant, thermal pad exposed on underside for board-level heat conduction.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MPC875ZT66, the MPC875ZT80 offers higher clock headroom for future firmware upgrades while maintaining full hardware compatibility, whereas the MPC885ZQ66 introduces architectural extensions (PCI, larger cache) that necessitate new PCB layout and driver adaptation - making it unsuitable as a drop-in replacement.

Availability

MPC875ZT66 is available at Aetrix Electronics and suitable for secure remote access gateways, industrial Ethernet controllers, ATM edge multiplexers, and USB device servers requiring stable component supply across extended temperature ranges (–40°C to +100°C junction).

Supply support for MPC875ZT66 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 Power Architecture™ microprocessors, delivering high-integration communications SoCs for networking and industrial markets from 1995–2015.

The MPC875ZT66 belongs to the PowerQUICC™ family - designed specifically for cost-sensitive, real-time communications applications where integrated FEC, security, and serial peripherals reduce system complexity versus discrete solutions.

FAQ

What is the maximum operating junction temperature for the MPC875ZT66?

The MPC875ZT66 has a maximum guaranteed junction temperature (TJ) of 100°C under extended temperature grade operation. This rating assumes proper thermal design using the specified 4-layer PCB with power/ground planes and thermal vias to the exposed pad. Exceeding TJ = 100°C risks permanent degradation of the security engine's cryptographic accelerators and cache coherency logic. Always validate thermal performance using the RθJB = 20°C/W parameter in your specific board layout.

Does the MPC875ZT66 support pin-compatible migration to higher clock speeds?

Yes - the MPC875ZT66 shares identical pinout, power sequencing, and thermal profile with the MPC875ZT80 (80 MHz) and MPC875ZT133 (133 MHz in 2:1 mode). All three variants use the same 256-ball PBGA package and require identical PCB layout. Migration requires only firmware updates to adjust PLL configuration and verify timing margins on external memory interfaces, as no hardware changes are needed.

How does the security engine in the MPC875ZT66 accelerate IPsec processing?

The MPC875ZT66 security engine accelerates IPsec by offloading AES-128/192/256 encryption/decryption, DES/3DES cipher operations, and SHA-1/256 hash generation directly in hardware. It uses a dedicated crypto-channel with DMA to process multi-command descriptors from CPU-allocated buffers, achieving >45 Mbps encrypted throughput at 66 MHz - freeing the main MPC8xx core for routing, firewall policy enforcement, and application tasks.

What are the mandatory reset configuration steps required for reliable MPC875ZT66 boot?

After HRESET deassertion, the MPC875ZT66 requires programming of six registers in boot code: SIUMCR[DBGC] = binary X1, MBMR[GPLB4DIS] = 0, PAPAR[5:9]/[12:13] = 0, PADIR[5:9]/[12:13] = 0, PBPAR[14:18]/[20:22] = 0, PBDIR[14:18]/[20:22] = 0, and PCPAR[4:5]/[8:9]/[14] = 0. Failure to configure these causes undefined port behavior and potential FEC initialization failure. These values are documented in Table 7 of the MPC875EC Rev. 4 specification.

Can the MPC875ZT66 operate with 5-V tolerant I/Os while powered at 3.3 V VDDH?

Yes - the MPC875ZT66 explicitly supports 5-V tolerant inputs on designated pins (e.g., PA[0:15], PB[14:31], MII_MDIO) when VDDH = 3.3 V, provided the input voltage does not exceed VDDH + 2.5 V (i.e., ≤5.8 V) and remains within absolute max ratings (≤5.5 V). However, outputs remain 3.3 V CMOS - level-shifting is required for driving true 5-V logic loads. This tolerance simplifies interfacing with legacy 5-V peripherals without external translators.