Google Groups no longer supports new Usenet posts or subscriptions. Historical content remains viewable.
Dismiss

[Question] PowerPC Timer Interrupt

39 views
Skip to first unread message

Hyun

unread,
Jan 8, 2010, 1:14:56 AM1/8/10
to
Hello!

Nowadays I try to use PowerPC in Linux. I am porting some codes which
were implemented for ARM core.

In this code, it can set timer interrupt with micro time unit. In
order to this, it uses OSCR, OSMR1, OIER registers, which exists in
pxa270 Processor (ARM core)

Actually, I want to implement this function on PowerPC, but I think
PowerPC doesn't provide registers for configuring timer interrupt.

The board which I use is GE Faunc VG5, and its mircoprocessor is
PowerPC MPC7455.
I read MPC7455 Manual, but I cannot find the register related to timer
interrupt. There is only timer count clock register. (TBU and TBL)

So, what is the method of implementing timer interrupt in PowerPC?
If I want to make an interrupt after 200us, how can I implement it in
Linux on PowerPC?

Please, if there are any one who knows well, let me know the method!

Have a good day!


Blunderbuss

unread,
Jan 9, 2010, 7:08:01 AM1/9/10
to
Hyun <hcse...@gmail.com> wrote:

> Actually, I want to implement this function on PowerPC, but I think
> PowerPC doesn't provide registers for configuring timer interrupt.
>
> The board which I use is GE Faunc VG5, and its mircoprocessor is
> PowerPC MPC7455.
> I read MPC7455 Manual, but I cannot find the register related to timer
> interrupt. There is only timer count clock register. (TBU and TBL)

The decrementer register is called DEC.

according to the docs, you can load it with mtspr 22

Hyun

unread,
Jan 11, 2010, 12:21:38 AM1/11/10
to
On 1월9일, 오후9시08분, blunderb...@double.dekker.not (Blunderbuss) wrote:

>
> The decrementer register is called DEC.
>
> according to the docs, you can load it with mtspr 22

Dear Blunderbuss,

Thank you for your reply.
I read the manual about DEC, and then I knew DEC is decrementer
register which can make exception.

But I don't know how to use it exactly.

If I want to make interrupt after 20 usec, May I just put the value of
(20 * tb_ticks_per_usec) into DEC and set MSR[EE] = 1?
(In linux/arch/powerpc/kernel/time.c, 100 ticks per usec)

Would you please tell me what the method to configure timer interrupt
with DEC is?

rvijay435

unread,
Sep 23, 2012, 2:01:50 PM9/23/12
to
Hi Hyun,
Is your issue resolved or still open ??????
Please let me know the status ASAP.


rvijay435
--
http://compgroups.net/comp.os.linux.powerpc/-question-powerpc-timer-interrupt/208266


0 new messages