Bureaucrats, dave_user, Administrators
4,650
edits
Changes
→Use case #1: headless system
Two custom power probes have been used:*power probe #1 is connected to the input power rail (12V) supplying the entire system*power probe #2 is connected to the input power rail of the PMIC NXP PF3000 (nominal voltage is 3.75V); this, in turn, powers the processor subsystem.=== Heavy load configurations===Measurements have been performed on the following platform (also denoted as testbed1 in the rest of the document):
* SBC Lynx rev.A (S-XUBB0110C1R)
* System software: XUELK 1.1.0
** U-Boot: U-Boot 2015.04-xuelk-1.1.0 (Nov 25 2016 - 16:43:19), Build: jenkins-XUELK_U-Boot-8
** Kernel: Linux sbc-lynx 3.14.52-xuelk-1.1.0-00026-g88e5473 #36 SMP PREEMPT Tue Dec 13 15:20:14 CET 2016 armv7l GNU/Linux
*root file system is stored on NAND flash
* processor's LDO is enabled (required to perform voltage scaling).
The following table shows the summary result of data collected at different checkpoints.
{|class="wikitable" style="text-align: center;"
|-
** uSD card: read/write/verify operations
** Ethernet: <code>iperf</code> TCP test running
=== Idle configurations ===
* SBC Lynx rev.A (S-XUBB0110C1R)
*** branch: http://gitlab.lan.dave.eu/lynx/linux-2.6-imx/commits/dev-1.1.0-powerConsumption
** RFS: R:\opt\nfsroot\lynx\xuelk-1.1.0-networking
* root file system stored in nand* ethernet on via ifconfigNAND flash
* CAN transceiver not present
===Optimized idle===
In this case the <code>powersave </code> governor is used. Most importantly, Ethernet interface is disabled, as described in i.MX 6UltraLite Power Consumption Measurement application note[2]. <ref name="AN5170">NXP Semiconductors, ''i.MX 6UltraLite Power Consumption Measurement'', Rev. 1, 04/2016</ref> This allows to reduce power consumption significantly because
* processor's peripheral bus can be disabled as well
* external PHY is put in power-down mode.
