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diff --git a/doc/openocd.texi b/doc/openocd.texi index cc133f7..cf41bc5 100644 --- a/doc/openocd.texi +++ b/doc/openocd.texi @@ -10981,6 +10981,64 @@ addreg rtest 0x1234 org.gnu.gdb.or1k.group0 system @end deffn +@section MIPS Architecture +@cindex microMIPS +@cindex MIPS32 +@cindex MIPS64 + +@uref{http://mips.com/, MIPS} is a simple, streamlined, highly scalable RISC +architecture. The architecture is evolving over time, from MIPS I~V to +MIPS release 1~6 iterations, the architecture is now able to handle various tasks +with different ASEs, including SIMD(MSA), DSP, VZ, MT and more. +MIPS32 supports 32-bit programs while MIPS64 can support both 32-bit and 64-bit programs. + +@subsection MIPS Terminology + +The term ASE means Application-Specific Extension, ASEs provide features that +improve the efficiency and performance of certain workloads, such as +digital signal processing(DSP), Virtualization(VZ), Multi-Threading(MT), +SIMD(MSA) and more. +The MIPS CPU Uses Coprocessors to configure its behaviour or to let software +know the capabilities of current CPU, the commonly used ones are Config0~3 Registers +and Status register. + +@subsection MIPS FPU & Vector Registers + +MIPS processors does not all comes with FPU co-processor, and when it does, the FPU +appears as Coprocessor 1 whereas the Coprocessor 0 is for the main processor. + +Most of MIPS FPUs are 64 bits, IEEE 754 standard, and they provides both 32-bit +single precision and 64-bit double precision calculations. Fixed point format +calculations are also provided with both 32 and 64-bit modes. + +The MIPS SIMD Architecture(MSA) operates on 32 128-bit wide vector registers. +If both MSA and the scalar floating-point unit (FPU) are present, the 128-bit MSA +vector registers extend and share the 64-bit FPU registers. MSA and FPU can not be +both present, unless the FPU has 64-bit floating-point register. + +@subsection MIPS Configuration Commands + +@deffn {Command} {mips32 cpuinfo} +Displays detailed information about current CPU core. This includes core type, +vendor, instruction set, cache size, and other relevant details. +@end deffn + +@deffn {Config Command} {mips32 scan_delay} [nanoseconds] +Display or set scan delay in nano seconds. A value below 2_000_000 will set the +scan delay into legacy mode. +@end deffn + +@deffn {Config Command} {mips32 cp0} regnum select [value] +Displays or sets coprocessor 0 register by register number and select. + +For common MIPS Coprocessor 0 registers, you can find the definitions of them +on MIPS Privileged Resource Architecture Documents(MIPS Document MD00090). + +For core specific cp0 registers, you can find the definitions of them on Core +Specific Software User's Manual, for example, MIPS M5150 Software User Manual +(MD00980). +@end deffn + @section RISC-V Architecture @uref{http://riscv.org/, RISC-V} is a free and open ISA. OpenOCD supports JTAG |