3 ms·
I'm aware of horizontal microprogramming,and I checked again but I still don't see your point. Maybe link a reference?
by deepnotderp 9y ago
I'm aware of horizontal microprogramming,and I checked again but I still don't see your point. Maybe link a reference?
- CalChris 9y agoSmotherman. A complete macroinstruction is executed by generating an appropriately timed sequence of groups of control signals (micro-operations). http://www.frsn.utn.edu.ar/tecnicas3/manuales/Microprogramming_hist.pdf http://www.frsn.utn.edu.ar/tecnicas3/manuales/Microprogrammi... Originally, RISC cpus were hardwired but they are general purpose ISAs. RISC-V is fixed 32b ISA but has multiple formats controlled by an opcode. https://image.slidesharecdn.com/20160130deckyfosdemportinghelenostorisc-v-160130115431/95/porting-helenos-to-riscv-20-638.jpg https://image.slidesharecdn.com/20160130deckyfosdemportinghe... Original microprogrammed CPUs had a writeable control store (WCS). Modern processors translate CISC instructions into μops and cache this translation. The difference is the μop cache (μstore) vs WCS. FWIW, Skylake also has a WCS for obscure instructions. Microinstructions, μops, do not have an opcode. They are not decoded. Bits in a horizontal μop gate logic on/off directly. The RISC-V people do say RISC-like. https://www2.eecs.berkeley.edu/Pubs/TechRpts/2016/EECS-2016-130.html https://www2.eecs.berkeley.edu/Pubs/TechRpts/2016/EECS-2016-... And even that's wrong. But then they never even define what a RISC is. So RISC-like could be anything.