NXP Semiconductors MC68302CEH20C

Overview

MC68302CEH20C from Freescale Semiconductor is a single-chip integrated multi-protocol processor featuring an MC68000/MC68008 microprocessor core, a dedicated RISC-based communications processor (CP), and a system integration block (SIB). It operates at 20 MHz, integrates 1152 bytes of on-chip dual-port RAM, supports HDLC/SDLC/UART/DDCMP/Totally Transparent protocols via three SCCs, and targets ISDN terminal adapters and data concentrators.

For engineers reviewing the MC68302CEH20C datasheet, MC68302CEH20C pinout, MC68302CEH20C application, or MC68302CEH20C equivalent, key selection criteria include its 20 MHz clock speed, triple SCC with protocol flexibility, dual-port RAM size, HCMOS TQFP-132 package compatibility, and support for concurrent multi-protocol operation without CPU intervention.

Technical Context

The MC68302CEH20C implements a tightly coupled architecture where the MC68000/MC68008 core handles general-purpose tasks while a separate RISC main controller in the CP manages serial communications autonomously. Its three full-duplex Serial Communication Controllers (SCCs) each support HDLC/SDLC, UART, DDCMP, Bisync, and Totally Transparent modes, with six dedicated serial DMA channels enabling frame buffering without CPU involvement.

System-level features include an IDMA controller, interrupt controller with two operation modes, four programmable chip-select lines with wait-state logic, DRAM refresh control, and hardware watchdog for bus activity monitoring. The on-chip clock generator provides output clock signals, and low-power standby modes are supported alongside freeze control for debugging peripherals.

Key Specifications

Pinout & Package

MC68302CEH20C is housed in a 132-pin Thin Quad Flat Pack (TQFP) package with 0.4 mm lead pitch, compliant with JEDEC MO-140AB. Pin assignments follow Motorola/Freescale standard layout for MC68302 derivatives, supporting multiplexed address/data bus, dedicated serial interface pins (SCC/SMC/SCP), parallel I/O ports with interrupt capability, and system control signals including reset, interrupt acknowledge, and bus arbitration lines.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC68EN302 and MC68LC302, the MC68302CEH20C uniquely balances 20 MHz performance, triple SCC flexibility, and ISDN/BRI protocol completeness in a 132-pin TQFP-making it optimal for cost-sensitive, protocol-diverse telecom edge devices where Ethernet or extreme low power are not primary requirements.

Availability

MC68302CEH20C is available at Aetrix Electronics and suitable for ISDN terminal adapters, data concentrators, and industrial modems requiring stable component supply across extended product lifecycles.

Supply support for MC68302CEH20C 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 leading designer of embedded processors and analog/mixed-signal ICs, with deep expertise in automotive, industrial, and networking silicon.

The MC68302CEH20C belongs to Freescale's integrated communications processor family, engineered specifically for telecom infrastructure edge devices needing concurrent multi-protocol serial processing without external co-processors.

FAQ

What is the maximum operating frequency of the MC68302CEH20C?

The MC68302CEH20C is rated for a maximum clock frequency of 20 MHz. This speed is guaranteed under specified voltage and temperature conditions per the original Freescale datasheet. The '20' in the part number explicitly denotes this 20 MHz rating, distinguishing it from other speed grades like MC68302CEH16C (16 MHz) or MC68302CEH25C (25 MHz). System timing budgets must account for bus setup/hold and peripheral wait-state requirements at this frequency.

Does the MC68302CEH20C support ISDN Basic Rate Interface (BRI) applications?

Yes, the MC68302CEH20C directly supports ISDN BRI applications through its three Serial Communication Controllers (SCCs), which implement HDLC/SDLC and LAPD protocols required for B-channel and D-channel framing. Its integrated clock generator and flexible physical interface support PCM and GCI timing needed for ISDN line interface chips. Freescale application notes AN1234 and AN1567 detail reference designs for MC68302CEH20C-based ISDN terminal adapters.

How much on-chip memory does the MC68302CEH20C include?

The MC68302CEH20C integrates 1152 bytes of dual-port static RAM on-die. This memory is accessible concurrently by both the MC68000/MC68008 CPU core and the RISC-based communications processor (CP), enabling efficient inter-processor communication without external FIFOs or shared memory arbitration logic. The memory map is programmable via system control registers to align with application-specific buffer allocation needs.

What package type is used for the MC68302CEH20C?

The MC68302CEH20C is packaged in a 132-pin Thin Quad Flat Pack (TQFP) with 0.4 mm lead pitch, conforming to JEDEC MO-140AB mechanical specifications. This surface-mount package supports automated PCB assembly and provides sufficient I/O density for its multiplexed address/data bus, three SCC interfaces, two SMCs, SCP, and parallel I/O ports. Thermal and mechanical data are documented in Freescale Package Outline Drawing #98ASB00106C.

Can the MC68302CEH20C operate without external RAM or ROM?

The MC68302CEH20C requires external memory for typical operation: its 1152-byte dual-port RAM is insufficient for full program execution or protocol stack storage. While the CPU core can boot from on-chip ROM if present (not included in MC68302CEH20C), the part relies on external code memory (e.g., EPROM or Flash) and additional data RAM. Four programmable chip-select lines facilitate connection to external memory devices with configurable wait-state insertion.