What is scratchpad memory?
Scratchpad memory isn't a &quot;type&quot; of memory. It is the purpose the memory is used for, but any type of memory could be used for that purpose.
Semiconductor marketing of course picked up on this confusion long ago: if there's a &quot;market&quot;, we shall fill it, and thus you had products designated as scratchpad (or cache!) RAM - they were simply &quot;small&quot; static RAMs, fast enough per whatever the marketing folk thought the typical scratchpad/cache use calls for. It's all marketing though: scratchpad/cache is what you make of it, not what it is :) And thus cache tag RAM wasn't merely called &quot;cache RAM&quot;, it was called tag RAM, because &quot;cache RAM&quot; was already the way fast SRAM in narrow DIP packages was peddled at the time.