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SocLib Components General Index
Mips Processor Functional Description
This hardware component is a Mips R3000 processor core. This uses the generic VciXcache component to interface a VCI advanced interconnect.
The simulation model is actually an instruction set simulator (ISS), organised as a three-stage pipeline:
- First stage: instruction fetch, with access to the external instruction cache.
- Second stage: instruction is executed with a possible access to the external data cache.
- Third stage: read memory access is written back to registers
The main functional specifications are the following:
- The patented LWL/LWR instructions are not implemented
- The floating point instructions are not supported
- There is no TLB, and no hardware support for virtual memory
- All Mips R3000 exceptions are handled, including the memory addressing X_IBE and X_DBE, but the write errors are not precise, due to the posted write buffer in the cache controller.
- A data cache line invalidation mechanism is supported: when a LW instruction is executed with the GPR[0] destination register, a cache line invalidation request is sent to the data cache.
Mips Processor CABA Implementation
The caba implementation is in
- source:trunk/soclib/systemc/include/caba/processor/mips.h
- source:trunk/soclib/systemc/src/caba/processor/mips.cc
- source:trunk/soclib/systemc/src/caba/processor/mips_jumps.cc
- source:trunk/soclib/systemc/src/caba/processor/mips_special.cc
- source:trunk/soclib/systemc/src/caba/processor/mips_decod.cc
Template parameters
This component has no template parameters.
Constructor parameters
Mips(
sc_module_name name, // Instance Name
int ident); // processor id
Visible registers
The following internal registers define the processor internal state, and can be inspected:
- PC : Program counter
- IR : Instruction register
- GPR[i] : General registers ( 0 < i < 32)
- HI & LO : Intermediate registers for multiply / divide instructions
- CP0_REG[i] : Coprocessor 0 registers (0<=i<32). Implemented values:
- 8: BAR : Bad address register
- 12: SR : Status register
- 13: CR : Cause register
- 14: EPC : Exception PC register
- 15: INFOS : CPU identification number on bits [9:0]
