AVR Core

In my simulation,I found the instruction pair of "rcall" and "ret" has some bugs. In Modelsim,after "rcall" the fuction, the instruction "ret" make the "pc" back to 0x0000, not the position after the "rcall" in the program. In "AVR studio" ,there is not this problem. I have not analysed the source code carefully now, And I'll do it later. Hope your reply! Thank you! Yours Mark 2008.2.27.

Hi Mark,

I just implemented the core on an Altera FPGA. I was able to compute some Fibanacci numbers using a recursive algorithm (this involves lots of rcall and ret). My design behaved well in the simulator and on target hardware. Have you done further investigations?

Otherwise I think the bug can be closed know.

Kind regards

Dave

Can you publish the source for the code that are producing the bug?

I am having the same problem with CALL. When a RET occurs the PC resets to 0000. Have you got any solution Mark?