Operating Modes: Normal, Network, and On-Demand

7.4Operating Modes: Normal, Network, and On-Demand

The ESSI has three basic operating modes and several data and operation formats. These modes are programmed via the ESSI control registers. The data and operation formats available to the ESSI are selected when you set or clear control bits in the CRA and CRB. These control bits are WL[2–1], MOD, SYN, FSL[1–0], FSR, FSP, CKP, and SHFD.

7.4.1Normal/Network/On-Demand Mode Selection

To select either Normal mode or Network mode, clear or set CRB[MOD]. In Normal mode, the ESSI sends or receives one data word per frame (per enabled receiver or transmitter). In Network mode, 2 to 32 time slots per frame can be selected. During each frame, 0 to 32 data words are received or transmitted (from each enabled receiver or transmitter). In either case, the transfers are periodic.

The Normal mode typically transfers data to or from a single device. Network mode is typically used in time division multiplexed networks of CODECs or DSPs with multiple words per frame.

Network mode has a submode called On-Demand mode. Set the CRB[MOD] for Network mode, and set the frame rate divider to 0 (DC = $00000) to select On-Demand mode. This submode does not generate a periodic frame sync. A frame sync pulse is generated only when data is available to transmit. The frame sync signal indicates the first time slot in the frame. On-Demand mode requires that the transmit frame sync be internal (output) and the receive frame sync be external (input). For simplex operation, Synchronous mode could be used; however, for full-duplex operation, Asynchronous mode must be used. You can enable data transmission that is data-driven by writing data into each TX. Although the ESSI is double-buffered, only one word can be written to each TX, even if the transmit shift register is empty. The receive and transmit interrupts function normally, using TDE and RDF; however, transmit underruns are impossible for On-Demand transmission and are disabled. This mode is useful for interfacing with codecs requiring a continuous clock.

Note: When the ESSI transmits data in On-Demand mode (that is, MOD = 1 in the CRB and DC[4–0]=$00000 in the CRA) with WL[2–0] = 100, the transmission does not work properly. To ensure correct operation, do not use On-Demand mode with the WL[2–0] = 100 32-bit word length mode.

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DSP56301 User’s Manual

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Motorola DSP56301 user manual Operating Modes Normal, Network, and On-Demand, Normal/Network/On-Demand Mode Selection
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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.
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