<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">fyi<br><div><br><div>Begin forwarded message:</div><br class="Apple-interchange-newline"><blockquote type="cite"><div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><font face="Helvetica" size="3" color="#000000" style="font: 12.0px Helvetica; color: #000000"><b>From: </b></font><font face="Helvetica" size="3" style="font: 12.0px Helvetica">Milosch Meriac <<a href="mailto:meriac@openmoko.org">meriac@openmoko.org</a>></font></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><font face="Helvetica" size="3" color="#000000" style="font: 12.0px Helvetica; color: #000000"><b>Date: </b></font><font face="Helvetica" size="3" style="font: 12.0px Helvetica">March 19, 2008 4:51:46 AM GMT+08:00</font></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><span class="Apple-style-span" style="-webkit-text-stroke-width: -1; "><font face="Helvetica" size="3" color="#000000" style="font: 12.0px Helvetica; color: #000000"><b>Subject: </b></font><font face="Helvetica" size="3" style="font: 12.0px Helvetica"><b>Re: Adding a system management MPU</b></font></span></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; min-height: 14px; "><br></div> </div>Hi Andy,<br><br>Andy Green wrote:<br><blockquote type="cite">Particularly as we established we are getting rid of U-Boot and have a<br></blockquote><blockquote type="cite">minimal bootloader, if we wake the CPU it means waking into Linux one<br></blockquote><blockquote type="cite">way or another before anything complicated gets done. We can use this<br></blockquote><blockquote type="cite">MPU to manage power and button/touchscreen/connector events, motion<br></blockquote><blockquote type="cite">sensors, battery HDQ, PMU, LEDs in a central, consistent and complete<br></blockquote><blockquote type="cite">way without needing to bring the CPU into it and without any dead time<br></blockquote><blockquote type="cite">while we wake the CPU.<br></blockquote><blockquote type="cite">Something along these lines (6.8mm x 6.8mm footprint) $3.10 / 100<br></blockquote><blockquote type="cite"><a href="http://focus.ti.com/docs/prod/folders/print/msp430f2272.html">http://focus.ti.com/docs/prod/folders/print/msp430f2272.html</a><br></blockquote><blockquote type="cite"><a href="http://www.ti.com/lit/gpn/msp430f2272">http://www.ti.com/lit/gpn/msp430f2272</a><br></blockquote><br>Funnily I chose a very similar chip for my Ebook Reader design - the MSP420F233 (dirt cheap and a supports lot of peripherals). Basically it allowed me to stick to a cheap PMU.<br>I attached all user peripherals to it: It controls the charging current by reading the USB id pin, controls the touch screen, wakes the CPU, controls the PMU and powersave modes, handles the vibration motor, measures voltages and currents, detects swapped SD cards, handles the cheaper accelerometer (analog interface only) and scans our touch screen. This allowed me in turn to put the CPU even into deep sleep and let the MSP430 decide when to wake it up (based on accelerometer readings etc.).<br>My main CPU (iMX31) talks to the MSP via as SPI master - the MSP toggles an IRQ line to request a status poll by the main CPU. The bluetooth module is shared by iMX and MSP - which allows great debugging and debricking action over Bluetooth/RFCOMM serial interface without opening the device at all - you are also able to see even early kernel boot messages over Bluetooth or reset the CPU over bluetooth. The MSP also handles the timer for alarm etc.<br><br>Warmest regards,<br>--<br>Milosch<br></blockquote></div><br></body></html>