R32V2020 Micro-Code

R32V2020 Microcode

• Each R32V2020 instruction executes 4 clocks of microcode
• Slots are w_OneHotState[0..3]
• 50 MHz clock rate
• 4 clocks = 12.5 MIPS

Bottleneck

• Pull from stack operation is the bottleneck
  • Due to pre-decrement

Signals asserted during w_OneHotState[]

• w_OneHotState[0]
  • o_clkInstrRomAddr
  • increment CPU cycle counter
• w_OneHotState[1]
  • i_Op_PULL
• w_OneHotState[2]
  • w_holdHaltCatchFire
  • o_writeStackRamEn
• o_writeToDataRamEnable
• w_OneHotState[3]
  • i_wrRegFile
  • o_peripheralRdStrobe
  • o_peripheralWrStrobe
  • i_save_CCR_bits
  • i_Op_PUSH
  • i_OP_BSR
  • i_Op_LPBP
  • i_Op_SPBP
  • i_Op_LPSP
  • i_Op_SPSP
  • i_Op_LPLP
  • i_Op_SPLP
  • i_Op_LDBP
  • i_Op_SDBP
  • i_Op_LDSP
  • i_Op_SDSP
  • i_Op_LDLP
  • i_Op_SDLP
  • Load Program Counter (pull PC)