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Motorola DSP56301 Internal Program Memory, Memory Switch Modes-Program Memory, Instruction Cache

Models: DSP56301

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Program Memory Space

3.1.1Internal Program Memory

The default on-chip program memory consists of a 24-bit-wide, high-speed, SRAM occupying the lowest 4 K (default), 3 K, 2 K, or 1 K locations in program memory space, depending on the settings of the OMR[MS] and SR[CE] bits. Section 4.3.2, Operating Mode Register (OMR), on page 4-12provides details on the MS bit. Section 4.3.1, Status Register (SR), on page 4-6provides details on the CE bit. The default on-chip program RAM is organized in 16 banks with 256 locations each (4 K). Setting the MS bit switches four banks of program memory to the X data memory and an additional four banks of program memory to the Y data memory. Setting the CE bit switches four banks of internal program memory to the Instruction Cache and reassigns its address to external program memory. The internal memory addresses for the Instruction Cache vary depending on the setting of the MS and CE bits. Refer to the memory maps in Section 3.7 for detailed information about the program memory configurations.

3.1.2Memory Switch Modes—Program Memory

Memory switch mode allows reallocation of portions of program RAM to X and Y data RAM. OMR[7] is the memory switch (MS) bit that controls this function, as follows:

νWhen the MS bit is cleared, program memory consists of the default 4 K × 24-bit memory space described in the previous section. In this default mode, the lowest

external program memory location is $1000. If the CE bit is set, the program memory consists of the lowest 3 K × 24-bits of memory space and the lowest external program

memory location is $0C00.

νWhen the MS bit is set, the highest 2 K × 24-bit portion of the internal program memory is switched to internal X and Y data memory. In this mode, the lowest

external program memory location is $800. If the CE bit is set and the MS bit is set, the program memory consists of the lowest 1 K × 24-bits of memory space and the lowest

external program memory location is $400.

3.1.3Instruction Cache

In program memory space, the location of the internal Instruction Cache (when enabled by the CE bit) varies depending on the setting of the MS bit, as noted above. Refer to the memory maps in Section 3.7 for detailed address information. When the instruction cache is enabled (that is, the SR[CE] bit is set), 1 K program words switch to instruction cache and are not accessible via addressing; the address range switches to external program memory.

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DSP56301 User’s Manual

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Motorola DSP56301 user manual Internal Program Memory, Memory Switch Modes-Program Memory, Instruction Cache
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DSP56301 specifications

The Motorola DSP56301 is a highly efficient digital signal processor, specifically engineered for real-time audio and speech processing applications. This DSP is part of Motorola's renowned DSP56300 family, which is recognized for its innovative features and outstanding performance in the realm of digital signal processing.

One of the main features of the DSP56301 is its ability to handle complex computations at high speeds. With a maximum clock frequency of 66 MHz, it delivers fast performance, enabling it to process audio signals in real time. The chip is built on a 24-bit architecture, which allows for high-resolution audio processing. This is particularly beneficial in applications such as telecommunications, consumer audio devices, and professional audio equipment, where precision is paramount.

The DSP56301 boasts a comprehensive instruction set that includes efficient mathematical operations, which are essential for digital filters and audio effects processing. One of the key innovations of this device is its dual data path architecture, which permits simultaneous processing of multiple data streams. This feature significantly enhances the device's throughput and responsiveness, making it suitable for demanding applications such as voice recognition and synthesis.

In terms of memory regions, the DSP56301 includes several on-chip memory categories, such as program memory, data memory, and a specialized memory for coefficients. The architecture's support for external memory expansion further increases its versatility, allowing designers to tailor systems to their specific requirements.

The DSP56301 implements advanced features such as a powerful on-chip hardware multiplier and accumulator, simplifying complex mathematical tasks and accelerating the execution of algorithms. Its flexible interrupt system enhances its capability to respond to time-sensitive operations, while the integrated serial ports facilitate efficient data communication with external devices.

Power consumption is also a vital characteristic of the DSP56301. It is designed with energy efficiency in mind, allowing for extended operation in battery-powered devices. The chip’s low power requirements are particularly advantageous in portable audio devices and other applications where energy conservation is crucial.

In conclusion, the Motorola DSP56301 is an exceptional digital signal processor that combines high processing power, flexibility, and efficiency. Its main features, advanced technologies, and robust architecture make it a top choice for developers seeking to create sophisticated audio and signal processing systems. With its enduring legacy in the industry, the DSP56301 continues to be relevant in a variety of modern applications, ensuring it remains a valuable tool for engineers and designers.