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Сигнальный МП Motorola DSP56002.pdf
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Freescale Semiconductor, Inc.

Freescale Semiconductor, Inc.

DSP56002 OPERATING MODE REGISTER (OMR)

 

23

8

 

 

7

6

5

4

3

2

1

0

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

*

 

 

*

SD

*

MC

YD

DE

MB

MA

OPERATING MODES A, B

DATA ROM ENABLE

INTERNAL Y MEMORY DISABLE

OPERATING MODE C

RESERVED

STOP DELAY

RESERVED

RESERVED

Figure 3-2 OMR Format

3.3.1Chip Operating Mode (Bits 0 and 1)

The chip operating mode bits, MB and MA, together with MC, define the program memory maps and the operating mode of the DSP56002. On processor reset, MB and MA are loaded from the external mode select pins, MODB and MODA, respectively. After the DSP leaves the reset state, MB and MA can be changed under software control.

3.3.2Data ROM Enable (Bit 2)

The DE bit enables the two, on-chip, 256X24 data ROMs located between addresses $0100–$01FF in the X and Y memory spaces. When DE is cleared, the $0100–$01FF address space is part of the external X and Y data spaces, and the on-chip data ROMs are disabled. Hardware reset clears the DE bit.

3.3.3Internal Y Memory Disable Bit (Bit 3)

Bit 3 is defined as Internal Y Memory Disable (YD). When set, all Y Data Memory addresses are considered to be external, disabling access to internal Y Data Memory. When cleared, internal Y Data Memory may be accessed according to the state of the DE control bit. The content of the internal Y Data Memory is not affected by the state of the YD bit. The YD bit is cleared during hardware reset.

Figure 3-1 DSP56002 Memory Maps shows a graphic representation of the DE and YD bit effects on the X and Y data memory maps. Table 3-1 also compares the DE and YD effects on the memory maps.

3 - 6 MEMORY MODULES AND OPERATING MODES MOTOROLA

For More Information On This Product, Go to: www.freescale.com

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