经典解决方案 : DS20E 's clock delay when power cycle

[sean.lu]

文档标题（能够清楚概括文章内容）：DS20E’s clock delay when power cycle

问题描述（要求清楚、明确）：

Hardware issues within DS20E can cause the "seconds" field of

the Time-Of-Year (TOY) Clock to be reset to "zero" on a power

cycle. All other fields (minutes, hours, day, month and year) are not

impacted.

解决说明：

Since the OS uses the TOY value to adjust its' time after a power

cycle, a reset of the "seconds" field can impact the accuracy of

the system clock.



History:





*The TOY is embedded in a complex Super IO device. This part is a

single sourced. There is no substitutable part and the part is no longer

being used in new designs.



*A process change in the manufacturing of the component, 18+ months

ago, severely impacted its use on the DS20E causing resets of the year,

month, day, and second fields in the TOY on a power cycle, which

resulted in a DS20E product hold.



NOTE: Older versions of the motherboard with older parts may not see

the TOY reset and time issue.



*The problem was narrowed to an internal sensitivity within the part

to the sequencing of the DS20E +3 and +5 volt lines and battery input.



*Due to the complexity of modifying the power supply sequencing to

cover all configuration requirements, which would have been time

consuming and very risky, a total solution could not be implemented.



*A DS20E engineering design change lessened the severity of the issue

by limiting the reset to the "seconds" field only. So the correct number

is less than 1'58''.



*A 100% screen was also put into manufacturing that included power

cycling stress test of DS20E systems checking all TOY clock values

except for the "seconds" field. This is a REV. J06 or later

motherboard.



STATUS:



The time of day provided by the TOY devices inside of Alpha systems is

not intended to be used as an accurate time source for the operation of

a business or time sensitiv

[hp-shamy · Accepted solution]

非常好！

[hp-shamy]

好