<story><title>Hacking the Timex m851</title><url>https://lock.cmpxchg8b.com/timex.html</url></story><parent_chain><item><author>nxobject</author><text>Part of the magic is how bonkers frugal the Epson SoC (PN S1C88349) is: when running at a low-power mode at 32kHz, it consumes an astoundingly low 9 &lt;i&gt;micro&lt;/i&gt;amps. [1] How much do you think you could get done with a cycle budget of 32k per second?&lt;p&gt;That, and alongside 48K ROM and 2K RAM, you get 3 timers, a UART, and an A&amp;#x2F;D converter.
[1] &lt;a href=&quot;https:&amp;#x2F;&amp;#x2F;global.epson.com&amp;#x2F;products_and_drivers&amp;#x2F;semicon&amp;#x2F;pdf&amp;#x2F;id002478.pdf&quot; rel=&quot;nofollow noreferrer&quot;&gt;https:&amp;#x2F;&amp;#x2F;global.epson.com&amp;#x2F;products_and_drivers&amp;#x2F;semicon&amp;#x2F;pdf&amp;#x2F;id...&lt;/a&gt;</text></item></parent_chain><comment><author>FirmwareBurner</author><text>&lt;i&gt;&amp;gt;Part of the magic is how bonkers frugal the Epson SoC (PN S1C88349) &lt;/i&gt;&lt;p&gt;Would it blow your mind that such ultra-frugal 8-bit parts have been available for about 30 years now?&lt;p&gt;Those Seiko-Epson chips, alongside with EM-Swatch, and OKI-Casio chips, were used in all kinds of timekeeping, calculator, thermometers, and all kinds of cheap low-power widgets with segment LCD displays that need to run years on a single button cell.&lt;p&gt;I have a calculator and a digital fever thermometer(the stick-type ones for the armpit or anus) that&amp;#x27;s over 15 years old, also using on one of those Seiko-Epson chips and it&amp;#x27;s still running on the same 1.5v button-cell that it came with, which is mind blowing when you factor in the charge decay of the lithium cell over time.</text></comment>
<story><title>Hacking the Timex m851</title><url>https://lock.cmpxchg8b.com/timex.html</url></story><parent_chain><item><author>nxobject</author><text>Part of the magic is how bonkers frugal the Epson SoC (PN S1C88349) is: when running at a low-power mode at 32kHz, it consumes an astoundingly low 9 &lt;i&gt;micro&lt;/i&gt;amps. [1] How much do you think you could get done with a cycle budget of 32k per second?&lt;p&gt;That, and alongside 48K ROM and 2K RAM, you get 3 timers, a UART, and an A&amp;#x2F;D converter.
[1] &lt;a href=&quot;https:&amp;#x2F;&amp;#x2F;global.epson.com&amp;#x2F;products_and_drivers&amp;#x2F;semicon&amp;#x2F;pdf&amp;#x2F;id002478.pdf&quot; rel=&quot;nofollow noreferrer&quot;&gt;https:&amp;#x2F;&amp;#x2F;global.epson.com&amp;#x2F;products_and_drivers&amp;#x2F;semicon&amp;#x2F;pdf&amp;#x2F;id...&lt;/a&gt;</text></item></parent_chain><comment><author>adhesive_wombat</author><text>There&amp;#x27;s an ultra-low power mode in newer TMS430s, and you can use an external ultra-low-power RTC.&lt;p&gt;From memory, it&amp;#x27;s under 100nA on paper, including things like the power switch leakage. Crazy stuff.</text></comment>