This version (27 Jul 2020 05:19) was approved by cathy fang.
Table of Contents
Introduction
This page describes the steps required to build and use the RTC on the ADSP-SC589 EZ-board(ADSP-SC584 and ADSP-SC573 don't support RTC). The Real Time Clock (RTC) serves two purposes: to keep accurate time/date information and to provide wake up alarms (both during runtime and while sleeping). Since the RTC can be externally powered and clocked independently of the processor it can remain running even when the rest of the system is turned off.
Hardware Required
An ADSP-SC589 EZ-Board v1.1 and above
Software Configuration
Configure Linux Kernel
Enable RTC support:
Device Drivers ---> [*] Real Time Clock ---> <*> ADI On-Chip RTC v2
Configure Packages
Add the rtc-test program in the filesystem images, it's enabled in adsp-sc5xx-full image by default.
vim build/conf/local.conf IMAGE_INSTALL_append = "rtc-test"
Example
Users just need to run rtc_test command on board to test rtc. Results as shown below:
# rtc_test 0. open and release opened '/dev/rtc0': fd = 3 1. ioctl RTC_UIE_ON 2. RTC read 5 times RTC read 1 RTC read 2 RTC read 3 RTC read 4 RTC read 5 3. ioctl RTC_UIE_OFF 4. Get RTC Time Current RTC date/time is 24-4-76, 22:48:15 5. Set RTC Time Set Current RTC date/time to 31-5-104, 02:30:00 Get RTC time Current RTC date/time is 31-5-104, 02:30:00 6. Set alarm Time 7. Get alarm Time Alarm time now set to 02:30:50 Waiting 50 seconds for alarm... random: nonblocking pool is initialized Okay. Alarm rang. Current RTC date/time is 31-5-104, 02:30:50 8. ioctl RTC_AIE_OFF 8.5 test sleep 10 Current RTC date/time is 31-5-104, 02:31:00 Current RTC date/time is 31-5-104, 02:31:00 RTC Tests done !
Back to Kernel Features and Device Drivers for ADSP-SC5xx Yocto Linux
resources/tools-software/linuxdsp/docs/linux-kernel-and-drivers/rtc/real_time_clock.txt · Last modified: 21 Jul 2020 10:00 by cathy fang