add slids
authorLuke Kenneth Casson Leighton <lkcl@lkcl.net>
Thu, 12 Jul 2018 02:56:28 +0000 (03:56 +0100)
committerLuke Kenneth Casson Leighton <lkcl@lkcl.net>
Thu, 12 Jul 2018 02:56:28 +0000 (03:56 +0100)
shakti/m_class/libre_riscv_chennai_2018.tex

index a6edf26d592d8d7b36a1d3f6c0140ba3801ba86f..c4a56725e1746faf5bb2107e5c2b33d9f8ad4054 100644 (file)
  \begin{itemize}
    \item Cover a lot of different scenarios (embedded, tablets, industrial,
          netbooks, crypto-currency mining).
-       \item Decent performance with high efficiency.  RISC-V: 40 \%
+       \item Decent performance with high efficiency.  RISC-V: 40\%
                  more efficient than ARM / Intel.  Shakti a good
              candidate: 2.5ghz and 120mW per core @ 22nm.
        \item 1080p video: y'all gotta watch cute kittens on youtube, right?
 }
 
 
+\frame{\frametitle{Challenging Stuff [4] - Power Management}
+
+ \begin{itemize}
+   \item Been done before, but not as a Libre Design.
+          \vspace{4pt}
+   \item GPIO Banks need per-bank VREF (1.8v? to 3.3v)\\
+             IO pads need built-in
+            level-shifting to convert to CPU VCORE
+          \vspace{4pt}
+   \item Each core needs independent variable-voltage capability
+            and independent shut-down (PMIC supplies external voltage)
+          \vspace{4pt}
+   \item DDR RAM still needs refreshing (even in sleep mode)
+          \vspace{4pt}
+   \item Extra RV32 (PicoRV32?) always-on core for wake-up / RTC?
+          \vspace{4pt}
+   \item PLLs are Analog.  fun fun fun in the sun sun sun...
+  \end{itemize}
+   {\it Really need help here.  PLLs, Analog stuff: very specific
+          domain expertise.  Fall-back: license proprietary HDL.
+   }
+}
+
+
 \frame{\frametitle{TODO}
 
  \begin{itemize}