RTC

Programming, for all ages and all languages.
Post Reply
ravi
Member
Member
Posts: 103
Joined: Fri Sep 08, 2023 10:46 am

RTC

Post by ravi »

Hello Octocontrabass

if i read and write elkhart lake RTC register with assembly in and out instruction (0x70 and 0x71)

RDC, 614109- chapter 27.2

but i if do it with mmio(FD00000h + 70h/71h) i am not able to do it. i am using the same procedure as we do with in and out instruction

thanks
Ravi
Octocontrabass
Member
Member
Posts: 5501
Joined: Mon Mar 25, 2013 7:01 pm

Re: RTC

Post by Octocontrabass »

That looks like a copy/paste error in the datasheet. You can't use MMIO to access the RTC.
tito
Posts: 1
Joined: Wed Jul 03, 2024 3:31 am

Re: RTC

Post by tito »

Hello Ravi,

i still get no valid values (most 0) reading RTC of Elkhart Lake using
asm out/in 70h/71h

and there is no entry in the windows device manager, where the resource is described.

So, i think, i must use mmio FD00000h + 70h/71h as descrbed in the Intel Document Number: 636722 Chap 26.2.

i am stil confused about this chapter. Is port io still supported?

do you got it working for Elkhart Lake? with which tech (pio or mmio)?

thank you
Tito
ravi
Member
Member
Posts: 103
Joined: Fri Sep 08, 2023 10:46 am

Re: RTC

Post by ravi »

Yes TiTo

I think MMIO didnot work

RTC works with 0x70/0x71.. in/out instructions
Post Reply