Yes, **broken link removed** offers Sun's T1 processor-core for free. I did not find it commercially usable at all -- which is probably why Sun gives it away for free. It is interesting for academic and research work, but not ready for 'drop-in' integration into an ASIC/FPGA project. (Well you can do that, but the T1 is very bad choice compared to other available cores, like ARM, MIPS, etc.)
LeonSPARC is VHDL. And the source-code uses a lot of VHDL-features (like record, enum, etc.), so it could be difficult for a beginner.
PacoBlaze is a from-scratch synthesizable & behavioral Verilog clone of Ken Chapman's popular PicoBlaze embedded microcontroller. KCAsm is a lightweight PicoBlaze assembler written in Java.
While Ken's version aims toward the most efficient implementation in the Xilinx FPGA architecture, PacoBlaze tries to be as configurable as possible, maintaining source code compatibility and code cycle accuracy with the original PicoBlaze. It also follows Xilinx guidelines for behavioral synthesis constructs mapping to Xilinx FPGA blocks. As there are actually 3 versions of the PicoBlaze microcontroller, PacoBlaze provides all PicoBlaze versions in one single Verilog file set.
The nice thing™ of having a behavioral Verilog model of PicoBlaze is that it is easier to modify, trim or expand the core in order to adapt it for special purpose applications (e.g. PacoBlaze mods with a multiply or bit count instructions). It also makes pure behavioral Verilog simulations possible; something really neat that has allowed many of its users to reach Nirvana. ;o)
Opencores only have code, not have report. It's difficult for you to understand and develop.
You should find in University's Project.
You can use Microblaze (32 bit)