ESSI Programming Model

7.5.2ESSI Control Register B (CRB)

CRB is one of two read/write control registers that direct the operation of the ESSI (see Figure 7-5). The CRB bit definitions are presented in Table 7-4. CRB controls the ESSI multifunction signals, SC[2–0], which can be used as clock inputs or outputs, frame synchronization signals, transmit data signals, or serial I/O flag signals.

23

22

21

20

19

18

17

16

15

14

13

12

 

 

 

 

 

 

 

 

 

 

 

 

REIE

TEIE

RLIE

TLIE

RIE

TIE

RE

TE0

TE1

TE2

MOD

SYN

 

 

 

 

 

 

 

 

 

 

 

 

11

10

9

8

7

6

5

4

3

2

1

0

 

 

 

 

 

 

 

 

 

 

 

 

CKP

FSP

FSR

FSL1

FSL0

SHFD

SCKD

SCD2

SCD1

SCD0

OF1

OF0

 

 

 

 

 

 

 

 

 

 

 

 

(ESSI0 X:$FFFFB6, ESSI1 X:$FFFFA6)

Figure 7-5.ESSI Control Register B (CRB)

The CRB contains the serial output flag control bits and the direction control bits for the serial control signals. Also in the CRB are interrupt enable bits for the receiver and the transmitter. Bit settings of the CRB determines how many transmitters are enabled: 0, 1, 2, or 3. The CRB settings also determine the ESSI operating mode. Either a hardware RESET signal or a software RESET instruction clears all the bits in the CRB. Table 7-2,Mode and Signal Definitions, on page 7-5summarizes the relationship between the ESSI signals SC[2–0], SCK, and the CRB bits.

The ESSI has two serial output flag bits, OF1 and OF0. The normal sequence follows for setting output flags when transmitting data (by transmitter 0 through the STD signal only).

1.Wait for TDE (TX0 empty) to be set.

2.Write the flags.

3.Write the transmit data to the TX register

Bits OF0 and OF1 are double-buffered so that the flag states appear on the signals when the TX data is transferred to the transmit shift register. The flag bit values are synchronized with the data transfer. The timing of the optional serial output signals SC[2–0]is controlled by the frame timing and is not affected by the settings of TE2, TE1, TE0, or the receive enable (RE) bit of the CRB.

The ESSI has three transmit enable bits (TE[2–0]), one for each data transmitter. The process of transmitting data from TX1 and TX2 is the same. TX0 differs from these two bits in that it can also operate in Asynchronous mode. The normal transmit enable sequence is to write data to one or more transmit data registers (or the Time Slot Register (TSR)) before you set the TE bit. The normal transmit disable sequence is to set the Transmit Data Empty (TDE) bit and then to clear the TE, Transmit Interrupt Enable (TIE), and Transmit Exception Interrupt

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DSP56301 User’s Manual

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Motorola DSP56301 user manual Essi Control Register B CRB, Shfd, OF1 OF0, ESSI0 X$FFFFB6, ESSI1 X$FFFFA6
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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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