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4096 bytes is 1024 words of 32 bits.
The IORD/IOWR macros read and write 32 bit words only, and it isn't an address that you give them, but a register number. When you do IORD(ONCHIP_MEMORY2_1_BASE, 0x3fe), the actual addresses accessed are the 4 bytes at ONCHIP_MEMORY2_1_BASE+4*0x3fe to ONCHIP_MEMORY2_1_BASE+4*0x3fe+3 (0x00011ff8 - 0x00011ffb).
When you do IOWR(ONCHIP_MEMORY2_1_BASE, 0x3fe, "THIS IS TO TEST HOW MUCH DATA CAN A MEMORY SPACE CONTAIN") you don't write the string to the onchip memory, you just write its address, which is a 32-bit word. The size of the string doesn't matter.
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Hi
I also have a problem with the on-chip memory in my project. I'm using a Cyclone 3c25 fpga and I once set my on-chip RAM to 60kb and the project did compile without any problem. But now it doesnt and I get error messages such as "error:can't fit RAM cells in design". If I'm correct the limit capacity of the on-chip RAM on this cyclone board is 66kb and it did work once. What could be the issue now?
Please help.
Honored Contributor
