From 4026d023279d18ff64166525aad952914328ce4a Mon Sep 17 00:00:00 2001 From: Daniel Schaefer Date: Tue, 10 Dec 2024 13:08:29 +0800 Subject: [PATCH] Mainboard: Add RTC battery information Signed-off-by: Daniel Schaefer --- Mainboard/README.md | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) diff --git a/Mainboard/README.md b/Mainboard/README.md index 5dba953..acbd7f6 100644 --- a/Mainboard/README.md +++ b/Mainboard/README.md @@ -254,3 +254,31 @@ as "JST SH", and has a 1.0 mm pitch. The same connector is used for the Speakers | 2 | FAN_SPEED | | 3 | FAN_PWM | | 4 | GND | + +## RTC Battery Interface + +NOTE: The mainboard will charge this battery, so a rechargable ML1220 battery MUST be used. +For example, CR2032 MUST NOT be used, it cannot be charged and will likely be damaged. + +RTC battery is used for storing persistent but resettable information. +This includes the time and DRAM training. Disconnection will result in deletion of that information. +If no battery is connection, DRAM training needs to happen on every boot, slowing down the boot process significantly. + +### Onboard RTC Battery + +Framework 13 Intel Core 11th through 13th Generation use an onboard coin cell battery as RTC. + +We use the Lotes LOTES_AAA-BAT-046-K01 connector. + +### RTC Battery Cable Connector + +On AMD Platforms and starting with Framework 13 Intel Core Ultra Series 1, no RTC battery is included anymore. +Settings are kept alive by the normal system battery. The only case where an +RTC battery is recommended, is when the system is used in standalone mode (without a battery). + +Cvilux CVILU_CI4402M1HRC-NH connector for the RTC Battery. + +| Pin | Signal | Location | +|-----|-----------|----------| +| 1 | +RTCBATT | Left | +| 2 | GND | Right |