This proposal adds a standardised extension instructions to the RV
instruction set by introducing a fixed small number N (e.g. N = 8) of
R-type opcodes xcmd0 rd, rs1, rs2, .. , xcmd7 rd, rs1, rs2, that are intended to be used as "overloadable" (slightly crippled) R-type instructions for independently developed extensions in the form of non standard CPU extensions, IP tiles, or closely coupled external devices.
This proposal adds a standardised extension instructions to the RV
instruction set by introducing a fixed small number N (e.g. N = 8) of
R-type opcodes xcmd0 rd, rs1, rs2, .. , xcmd7 rd, rs1, rs2, that are intended to be used as "overloadable" (slightly crippled) R-type instructions for independently developed extensions in the form of non standard CPU extensions, IP tiles, or closely coupled external devices.