Port E Direction Register Prre, PRRE1 PRRE0

GPIO Signals and Registers

8.7.2Port E Direction Register (PRRE)

The read/write PRRE controls the direction of SCI GPIO signals. When port signal[i] is configured as GPIO, PRRE[i] controls the port signal direction. When PRRE[i] is set, the GPIO port signal[i] is configured as output. When PRRE[i] is cleared, the GPIO port signal[i] is configured as input. A hardware RESET signal or a software RESET instruction clears all PRRE bits.

23	22	21	20	19	18	17	16	15	14	13	12


11	10	9	8	7	6	5	4	3	2	1	0

PRRE2

PRRE1

PRRE0

Note: For bits 2–0, a 0 configures PEn as a GPI and a 1 configures PEn as a GPO. For the SCI, the GPIO signals are PE[2–0]. The corresponding direction bits for Port E GPIOs are PRRE[2–0].

= Reserved. Read as zero. Write with zero for future compatibility.

Figure 8-9.Port E Direction Register (PRRE X:$FFFF9E)

8.7.3Port E Data Register (PDRE)

Bits 2–0 of the read/write 24-bit PDRE writes data to or reads data from the associated SCI signal lines when configured as GPIO signals. If a port signal PE[i] is configured as an input (GPI), the corresponding PDRE[i] bit reflects the value present on the input signal line. If a port signal PE[i] is configured as an output (GPO), a value written to the corresponding PDRE[i] bit is reflected as a value on the output signal line. Either a hardware RESET signal or a software RESET instruction clears all PDR bits.

23	22	21	20	19	18	17	16	15	14	13	12


11	10	9	8	7	6	5	4	3	2	1	0

PDRE2

PDRE1

PDRE0

Note: For bits 2–0, the value represents the level that is written to or read from the associated signal line if enabled as a GPIO signal by the PCRE bits. For SCI, the GPIO signals are PE[2–0]. The corresponding data bits are PDRE[2–0].

= Reserved. Read as zero. Write with zero for future compatibility.

Figure 8-10.Port Data Registers (PDRE X:$FFFF9D)

Serial Communication Interface (SCI)

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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.

Motorola DSP56301 Port E Direction Register Prre, Port E Data Register Pdre, PRRE1 PRRE0

Models: DSP56301