Il 18/04/2008 8.50, isnithin ha scritto:

> Hi,
>          I am using LTC2950 ON/OFF controller to switch on the
> device........
> 
> 4.The Kill input is connected to one of the GPIO pins of the processor
> 5. The condition is that the processor needs to send a high signal to the
> LTC2950 within 512 ms from where it generates enable output signal.

Doing exactly same thing here, now. Using LTC2953, very similar.

Suggestions:

- check your clock oscillation startup time
- check reset release time
- use INITCODE fragment at the beginning of your LDR file to setup sdram 
controller *AND* pull high that KILL signal.
An INITCODE fragment runs as soon as it's loaded from flash, directly 
from L1. 500 ms it's a plenty of time to do that.
- to debug that, just see with a scope how long it takes to pull up KILL 
from power up.

How to do and INITCODE ?
You really should know, because it's almost always needed to flash your 
code. Please read the manuals, it's all there, in detail.


>    Now,  will I be able to generate the enable signal within that short
> time(512 ms) because the system needs to boot up and generate the enable
> output signal.....
> 
> Switch OFF steps
> 1.when switch  button is pressed, it generates the NMI interrupt....
> 2. Now, Can I genertae the interrupt routine with that generated NMI 
> interrupt  to put the processor in sleep or deep sleep mode.......
> 
> Please reply to my both problems
> 

Also this is covered in detail in the manuals.
Please do your homework first: read the manuals, really.
There's simply too much things that can go wrong, if you ignore them.

I will give you the answers to all of your questions regarding BlackFin 
if you have an answer to the one question of mine: do you have money?



Vladimir Vassilevsky
DSP and Mixed Signal Design Consultant
http://www.abvolt.com




isnithin wrote:

> Hi,
>          I am using LTC2950 ON/OFF controller to switch on the
> device........
> 
> Switch On steps.......
> 1.when switch button is pressed, it generates the enable output signal
> which in turn enables the DC/DC converter..
> 2. The output of the DC/ DC converter is given to input VDDEXT pins of the
> processor and many other devices to power ON
> 3. LTC 2950 has an KILL input which needs to be controlled by the
> processor
> 4.The Kill input is connected to one of the GPIO pins of the processor
> 5. The condition is that the processor needs to send a high signal to the
> LTC2950 within 512 ms from where it generates enable output signal.
>    Now,  will I be able to generate the enable signal within that short
> time(512 ms) because the system needs to boot up and generate the enable
> output signal.....
> 
> Switch OFF steps
> 1.when switch  button is pressed, it generates the NMI interrupt....
> 2. Now, Can I genertae the interrupt routine with that generated NMI 
> interrupt  to put the processor in sleep or deep sleep mode.......
> 
> Please reply to my both problems
> 

Hi,
         I am using LTC2950 ON/OFF controller to switch on the
device........

Switch On steps.......
1.when switch button is pressed, it generates the enable output signal
which in turn enables the DC/DC converter..
2. The output of the DC/ DC converter is given to input VDDEXT pins of the
processor and many other devices to power ON
3. LTC 2950 has an KILL input which needs to be controlled by the
processor
4.The Kill input is connected to one of the GPIO pins of the processor
5. The condition is that the processor needs to send a high signal to the
LTC2950 within 512 ms from where it generates enable output signal.
   Now,  will I be able to generate the enable signal within that short
time(512 ms) because the system needs to boot up and generate the enable
output signal.....

Switch OFF steps
1.when switch  button is pressed, it generates the NMI interrupt....
2. Now, Can I genertae the interrupt routine with that generated NMI 
interrupt  to put the processor in sleep or deep sleep mode.......

Please reply to my both problems

-- 
Kind Regards,
Nithin K S