Motorola MCF5281, MCF5282 user manual Sram, Flash, Debug Module

Models: MCF5282 MCF5281

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MCF5282 Key Features

as temporary storage during miss processing. For all data cache configurations, the memory operates in write-through mode and all operand writes generate an external bus cycle.

1.1.1.2SRAM

The SRAM module provides a general-purpose 64-Kbyte memory block that the ColdFire core can access in a single cycle. The location of the memory block can be set to any 64-Kbyte boundary within the 4-Gbyte address space. The memory is ideal for storing critical code or data structures, for use as the system stack, or for storing FEC data buffers. Because the SRAM module is physically connected to the processor's high-speed local bus, it can quickly service core-initiated accesses or memory-referencing commands from the debug module.

The SRAM module is also accessible by non-core bus masters, for example the DMA and/or the FEC. The dual-ported nature of the SRAM makes it ideal for implementing applications with double-buffer schemes, where the processor and a DMA device operate in alternate regions of the SRAM to maximize system performance. As an example, system performance can be increased significantly if Ethernet packets are moved from the FEC into the SRAM (rather than external memory) prior to any processing.

1.1.1.3Flash

This product incorporates SuperFlash® technology licensed from SST. The ColdFire Flash Module (CFM) is a non-volatile memory (NVM) module for integration with the processor core. The CFM is constructed with eight banks of 32K x 16-bit Flash arrays to generate 512 Kbytes of 32-bit Flash memory

NOTE

The CFM on the MCF5281 is constructed with four banks of 32K x 16-bit Flash arrays to generate 256 Kbytes of 32-bit Flash memory.

These arrays serve as electrically erasable and programmable, non-volatile program and data memory. The Flash memory is ideal for program and data storage for single-chip applications allowing for field reprogramming without requiring an external programming voltage source. The CFM interfaces to the V2 ColdFire core through an optimized read-only memory controller which supports interleaved accesses from the 2-cycle Flash arrays. A “backdoor” mapping of the Flash memory is used for all program, erase, and verify operations. It also provides a read datapath for non-core masters (for example, DMA).

1.1.1.4Debug Module

The ColdFire processor core debug interface is provided to support system debugging in conjunction with low-cost debug and emulator development tools. Through a standard

MOTOROLA

Chapter 1. Overview

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Motorola MCF5281, MCF5282 user manual Sram, Flash, Debug Module