Please read the following table in HTML format from a webpage and then answer the question in detail according to the table. Each table cell is defined by a <td> and a </td> tag. Each table row starts with a <tr> and ends with a </tr> tag. 'rowspan=m' and 'colspan=n' represents a cell spaning over 'm' rows and 'n' columns.

Webpage title:
Motorola 68000 series
Table title:
Feature map
Table:
<table id='hittask' contenteditable='False'>
<tr> <th colspan=1 rowspan=1 > Year </th><th colspan=1 rowspan=1 > CPU </th><th colspan=1 rowspan=1 > Package </th><th colspan=1 rowspan=1 > Frequency (max) [in MHz] </th><th colspan=1 rowspan=1 > Address bus bits </th><th colspan=1 rowspan=1 > MMU </th><th colspan=1 rowspan=1 > FPU </th></tr>
<tr> <td colspan=1 rowspan=1 > 1979 </td><td class="highlighted"  colspan=1 rowspan=1 > 68000 </td><td colspan=1 rowspan=1 > 64-pin dual in-line package (DIP), 68-pin LCC, 68-pin pin grid array (PGA) </td><td colspan=1 rowspan=1 > 8–20 </td><td colspan=1 rowspan=1 > 24 </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <td colspan=1 rowspan=1 > 1982 </td><td colspan=1 rowspan=1 > 68010 </td><td colspan=1 rowspan=1 > 64-pin DIP, 68-pin PLCC, 68-pin PGA </td><td colspan=1 rowspan=1 > 8–16.67 </td><td colspan=1 rowspan=1 > 24 </td><td colspan=1 rowspan=1 > 68451 </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <td colspan=1 rowspan=1 > 1984 </td><td class="highlighted"  colspan=1 rowspan=1 > 68020 </td><td colspan=1 rowspan=1 > 114-pin PGA </td><td colspan=1 rowspan=1 > 12.5–33.33 </td><td colspan=1 rowspan=1 > 32 </td><td colspan=1 rowspan=1 > 68851 </td><td colspan=1 rowspan=1 > 68881 </td></tr>
<tr> <td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 > 68EC020 </td><td colspan=1 rowspan=1 > 100-pin Quad Flat Package (QFP) </td><td colspan=1 rowspan=1 > 16.7–25 </td><td colspan=1 rowspan=1 > 24 </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <td colspan=1 rowspan=1 > 1987 </td><td colspan=1 rowspan=1 > 68030 </td><td colspan=1 rowspan=1 > 132-pin QFP (max 33 MHz), 128-pin PGA </td><td colspan=1 rowspan=1 > 16–50 </td><td colspan=1 rowspan=1 > 32 </td><td colspan=1 rowspan=1 > MMU </td><td colspan=1 rowspan=1 > 68881 </td></tr>
<tr> <td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 > 68EC030 </td><td colspan=1 rowspan=1 > 132-pin QFP, 128-pin PGA </td><td colspan=1 rowspan=1 > 25 </td><td colspan=1 rowspan=1 > 32 </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 > 68881 </td></tr>
<tr> <td colspan=1 rowspan=1 > 1991 </td><td class="highlighted"  colspan=1 rowspan=1 > 68040 </td><td colspan=1 rowspan=1 > 179-pin PGA, 184-pin QFP </td><td colspan=1 rowspan=1 > 20–40 </td><td colspan=1 rowspan=1 > 32 </td><td colspan=1 rowspan=1 > MMU </td><td colspan=1 rowspan=1 > FPU </td></tr>
<tr> <td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 > 68LC040 </td><td colspan=1 rowspan=1 > PGA, 184-pin QFP </td><td colspan=1 rowspan=1 > 20–33 </td><td colspan=1 rowspan=1 > 32 </td><td colspan=1 rowspan=1 > MMU </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 > 68EC040 </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 > 20–33 </td><td colspan=1 rowspan=1 > 32 </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <td colspan=1 rowspan=1 > 1994 </td><td class="highlighted"  colspan=1 rowspan=1 > 68060 </td><td colspan=1 rowspan=1 > 206-pin PGA </td><td colspan=1 rowspan=1 > 50–75 </td><td colspan=1 rowspan=1 > 32 </td><td colspan=1 rowspan=1 > MMU </td><td colspan=1 rowspan=1 > FPU </td></tr>
<tr> <td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 > 68LC060 </td><td colspan=1 rowspan=1 > 206-pin PGA, 208-pin QFP </td><td colspan=1 rowspan=1 > 50–75 </td><td colspan=1 rowspan=1 > 32 </td><td colspan=1 rowspan=1 > MMU </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 > 68EC060 </td><td colspan=1 rowspan=1 > 206-pin PGA </td><td colspan=1 rowspan=1 > 50–75 </td><td colspan=1 rowspan=1 > 32 </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 >  </td></tr>
</table>
Question:
What naming protocol did Motorola use for its CPU cores?
Answer:
Motorola used numbers for CPU core such as 68000, 68020, 68040 and 68060.