On Saturday 14 February 2009 03:48, chintanjoshi2008 wrote:
> Hi,
> In which cases do we need to use pull up or pull down resisters?
Err.. i think you are in the wrong end of the pool. But...
Pullup when you want a high and pull down when you want a low.
> I need to interface some gates and buffers to the
gpio pins of
> LPC2148 as dead time generator circuit.
> 1.Is there any dead time register available in LPC2148's PWM module
> as in case of some Texas instrument's DSPs or will I have to use
> timers and capture interrupts?
> 2.how would I know if the logic family I am using is compatible
> with LPC2148 or not e.g. say 74ls00 or 74hc00 or 74hc132?
I am sure you are in the deep end of the pool without knowing anything
about swimming.
> 3.can you suggest some technical documents which can
help me in
> this regards.
The LPC2148 hardware manual AND the ttl device manuals.
> 4.what may happen if I interface an IC which is not
compatible to
> output levels of LPC2148?
It depends. Sometimes they die quietly some times with a wisp of
smelly smoke. sometimes with a nice entertaining bang. On the rare
occasion it might be really entertaining - ignites a nice bonfire and
require evacuation of the building.
You need to read up on basic digital logic gates, fan-in, fanout, gate
delays, tristate, . Google is the perfect place to start.
--
Rgds
JTD