Code optimisation

Hello,

I am beggining to use the NIOS II development kit, Cyclone II edition. The examples are working well.

Now I am trying to make a design with the UART link, the LCD and one led. First, I used the reduced C library in order to optimise code (I am only using ON-chip memory). But now, I want to use the fopen() function and this is not supported under the small C library.

I have done all what is preconised in the SW developpers Handbook 4-23 and later.

Now, when I compile the code, I do not have enough memory (44 kbytes on-chip memory).

But if I try to increase the on-chip memory. The hardware design does not fit anymore.

I have then some questions :

- What is the size of the cells in bits when Quartus II returns :" 246 RAM cells cannot be placed" ?

- In the NIOS II SW developpers Handbook 4-27, there's a paragraph explaining that we can remove device drivers if we don't want it. But I don't understand how to remove the UART driver for example. Does anybody knows ?

- Are there other tips in order to optimise code or do I have to had external memory ?

Thank you for any help,

Jean LEE