AM335x RTC Usage

= Date Created/Modified =

Created :  January 21, 2014 - WORK IN PROGRESS Modified :  ~January 21, 2014

= Overview =

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KEY: The "AM335x RTC Usage" topic provides an overview of different RTC options when using the AM335x, Sitara family of processors. There is a high level description of 3 topolgies followed by implementation details of 2 of them. Where possible, real use-case details and compiled data from TI AM3358 EVM will be used.
 * AM335x refers to any of the 5 devicew within the AM335x family. http://www.ti.com/lsds/ti/arm/sitara_arm_cortex_a_processor/sitara_arm_cortex_a8/am335x_arm_cortex_a8/products.page?paramCriteria=no
 * TI AM3358 EVM will be used as HW platform for test data
 * TI AM3358 EVM uses the companion PMIC TPS65910A3 and this will be used as HW platform for test data below

As with most things in embedded processing there are trade-offs that one may have to make in order to minimize system cost or reduce SW complexity, etc. Where necessary the pros/cons of each use-case will be detailed.

RTC Options

 * 1) AM335x integrated RTC block + crystal
 * 2) AM335x companion PMIC device with integrated RTC block + crystal
 * 3) External RTC device with dedicated crystal

NOTE: In use-cases 1 and 2, there is a choice of using external crystal to improve accuracy. Details along with pros/cons covered below.


 * AM335x internal RTC block with external crystal
 * TPS65910A31 internal RTC block with external crystal

settings that were used to perform such power measurements. This collection of real power measurements was measured on an AM335x GP EVM with a high-precision digital multimeter. For additional details about the AM335x processor, please visit the TI.com product page.

TOPIC
The xxxxxxx on the following platform:


 * Texas Instruments AM335x 15x15 GP EVM
 * Base Board
 * Base Board

Base Board SW3 settings

Base Board SW4 settings


 * Keithley 2701 DMM with a 7702 40-channel mux module.
 * All tests were not conducted in a controlled environment. The ambient room temperature was ~25C.