Figures 2.15 to 2.17 show the control method from the CPU step by step. Figure 2.15 Loading DSP program Step1
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Figure 2.16 Loading DSP program Step2
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Figure 2.17 Loading DSP program Step3
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●DSP data access
To access DSP data, you can use the DSP's DMA instructions, but you can also access the DSP's data RAM area from the main CPU. Data can be accessed by controlling from the main CPU in the order shown below.
- Set bit16 and bit17 of the program control port to 0.
- Writes the access start address to the data RAM address port. It cannot be set unless the DSP is stopped.
- Data is accessed sequentially in longword units via the data RAM data port.
Figures 2.18 to 2.20 show the control method from the CPU step by step. Figure 2.18 DSP data access step1
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Figure 2.19 DSP data access step 2
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Figure 2.20 DSP data access step 3
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●Start execution of DSP program
To start executing the DSP program, write 1 to bit 16 of the program control port (see Figure 2.21). When the DSP recognizes that it has been written, it begins execution from the address stored in the program RAM address of the program control port. Therefore, the execution start address must be set before writing 1 to bit 16 of the program control port. Figure 2.21 DSP program execution start control from CPU
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●Forced stop of DSP program
To forcibly stop the execution of a DSP program, write 0 to bit 16 of the program control port, which is the opposite of starting execution. Figure 2.22 shows forced stop control. Figure 2.22 Forced stop control of DSP program from CPU
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