SCI Initialization

There are two workarounds for this issue:

νEnable an SCI pin other than SCLK.

νIn the next instruction, enable the remaining SCI pins, including the SCLK pin.

Following is an example of one way to initialize the SCI:

1.Ensure that the SCI is in its individual reset state (PCRE = $0).

2.Configure the control registers (SCR, SCCR) according to the operating mode, but do not enable transmitter (TE = 0) or receiver (RE = 0).

Note: It is now possible to set the interrupts enable bits that are used during the operation. No interrupt occurs yet.

3.Enable the SCI by setting the PCRE bits according to which signals are used during operation.

4.If transmit interrupt is not used, write data to the transmitter.

Note: If transmitter interrupt enable is set, an interrupt is issued and the interrupt handler should write data into the transmitter. The DMA channel services the SCI transmit request if it is programmed to service the SCI transmitter.

5.Enable transmitters (TE = 1) and receiver (RE = 1) according to use. Operation starts as follows:

νFor an internally-generated clock, the SCLK signal starts operation immediately after the SCI is enabled (Step 3 above) for Asynchronous modes. In Synchronous mode, the SCLK signal is active only while transmitting (that is, a gated clock).

νData is received only when the receiver is enabled (RE = 1) and after the occurrence of the SCI receive sequence on the RXD signal, as defined by the operating mode (that is, idle line sequence).

νData is transmitted only after the transmitter is enabled (TE = 1), and after the initialization sequence has been transmitted (depending on the operating mode).

8.4.1Preamble, Break, and Data Transmission Priority

Two or three transmission commands can be set simultaneously:

νA preamble (TE is set.)

νA break (SBK is set or is cleared.)

νAn indication that there is data for transmission (TDRE is cleared.)

Serial Communication Interface (SCI)

8-7

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Motorola DSP56301 user manual Preamble, Break, and Data Transmission Priority
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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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