question about ICD

[hayee]

I have a question about ICD.
I am using pic16f870 and ccs compiler version 4.020.when i compile the program without enabling ICD it takes 84% of RAM
and 91% of ROM but when i enable the ICD option (#device ICD=true) it creates an error
"not enough ram for all variables".

when i use pic16f877a (i know that its memory is big as compare to pic16f870) and enable ICD option (#device ICD=true) it takes 30% of RAM and 23% of ROM and when i disable the ICD option it takes 29% of RAM and 22% of ROM.I am only doing this comparision because i want to know that how much RAM and ROM ICD use but i can't find my answer.
Is Anyone know that how much RAM and ROM ICD use? and why error is generating in PIC16f870.

[PCM programmer]

I don't know if CCS publishes the resources that are used by the ICD.
But the MPLAB help file for the ICD2 does have a list of all the resources
used by the ICD2. This thread has instructions to find it in the help file:
http://www.ccsinfo.com/forum/viewtopic.php?t=28020