[PIC] making a big table of constants in program space?

[MathGeek]

c30 creating constants in program space

I am trying to make a good size table of constants.

I am using dsPIC30F4011, and although it has a good size RAM, I am reserving that for other purposes, and need to use the even bigger program (code) space for storing a table of constants.

I am using C30, and would like to do this.

I just need some key points and guiding remarks on how to get started.

Thanks.

 

[z01z]

You can store constants in C like this:

const unsigned char numbers[10][8]=
	{{0x1C, 0x22, 0x26, 0x2A, 0x32, 0x22, 0x1C, 0x00},
	 {0x08, 0x18, 0x08, 0x08, 0x08, 0x08, 0x1C, 0x00},
	 {0x1C, 0x22, 0x02, 0x04, 0x08, 0x10, 0x3E, 0x00},
	 {0x1C, 0x22, 0x02, 0x0C, 0x02, 0x22, 0x1C, 0x00},
	 {0x04, 0x08, 0x10, 0x24, 0x3E, 0x04, 0x04, 0x00},
	 {0x3E, 0x20, 0x20, 0x3C, 0x02, 0x02, 0x3C, 0x00},
	 {0x1C, 0x22, 0x20, 0x3C, 0x22, 0x22, 0x1C, 0x00},
	 {0x3E, 0x02, 0x02, 0x04, 0x08, 0x10, 0x20, 0x00},
	 {0x1C, 0x22, 0x22, 0x1C, 0x22, 0x22, 0x1C, 0x00},
	 {0x1C, 0x22, 0x22, 0x1E, 0x02, 0x22, 0x1C, 0x00}};

 

[MathGeek]

that is part of my question. does "const" store the value into program space or precious RAM?

Which datasheet should I look into? C30 manual? 30F programmer's manual?

 

[z01z]

Definitely the C30 manual. I don't know how this compiler handles constants, but gcc for example uses program space to store constants. I guess the C30 does the same, but you better check it.