Floating Point Numbers in #ROM Statement

[whmeade10]

I understand what the #ROM statement is used for and how to place integers at compliation time. I am using a PIC18F242 and need to place 2 floating point numbers in the internal eeprom when the chip is programed.

I have 5 numbers to store using the #ROM statement.

#1 - 5 in location 0
#2 - 2 in location 1
#3 - 10.0 in location 2,3,4,5
#4 - 100.0 in location 6,7,8,9
#5 - 15 in location 10

#rom int 0xf00000={5,1,?,?,?,?,?,?,?,?,10}

Thanks for taking a look at my question...

[epideath]

You can do this. It won't allow you to specify where in memory to put it. but it will allocate it in the Program Rom vs. RAM.

Not sure if that will meet your needs or not.


float const SomeValue[] = {1.0,2.0,3.0};


Hope this helps

[Ttelmah]

Er. I'm sorry 'epideath', but you are wrong. The ROM statement as posted, will work exactly as he wants to put a number in the EEPROM.
In the CCS directory, there is a little 'tool, called 'Pconvert.exe'. This tells you what bytes represent a float, so type in the '10.0' into the float window, and the 'hex' widow, will give the pattern '82200000', which is what needs to go in place of the first for question marks. I'll leave the poster to work out the next four bytes.

Best Wishes

[whmeade10]

Thanks for your quick reply I will give it a try tonight.

[epideath]

[Ttelmah]

The problem is that your 'alternative', won't work.
#ROM, allows you to put a sequence of bytes anywhere in ROM, whether program space, or EEPROM. You can even define the date 'type' to be placed, when working in the program space (int16 or int8 - unfortunately, this doesn't support a 'float' - a real pity..).
The 'const' statement, doesn't just place the data, but generates a 'program' to retrieve the data as well. As such, it only works for the program memory space, and not the EEPROM, and can't be used to put a defined block of data directly 'at' a location in memory, since the header 'program', will result in the actual data being placed a little further on in the memory space than expected. You can define where to put a 'const' (you say that you can't) - since it is a 'program', you use: