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Discussion Groups | LPC900 | PUSH SP
Find help, specifications and source code for the LPC900. The LPC900 challenges Microchip and AVR based on the worlds most popular 8-bit architecture the 80C51. With a 2-clock core the LPC900 series is a high performance, very flexible and low cost 8-bit microcontroller family. Designers using or interested in these devices are encouraged to share their know-how and ask questions.
PUSH SP - wekovci - Mar 16 7:12:00 2005
Hello all,
I would like to ask you to do a little test for me (I don't have a
single LPC9xx to try...).
There was a discussion on 8052.com on the effect of PUSH SP on various
'51 variants:
http://www.8052.com/forum/thread.phtml?thread=89005
and it turned out, that various Philips parts behaved in a different
way.
The testing code was the following:
mov SCON,#52h ;set serial mode 1 + preset ti
mov TMOD,#21h
mov TH1,#-12 ;2400@2400...
setb tr1 ;enable timer 1
mov t2con,#20h ;only RCLK
mov sp,#7
push sp
jnb ti,$
clr ti
mov sbuf,8
jnb ti,$
clr ti
pop sp
mov sbuf,sp
stop:
ljmp stop
end
It sends out 2 characters (numbers) to the serial port (07h or 08h),
so they have to be captured on a terminal program capable of
displaying hexadecimal numbers.
This is for the standard '51, so the serial port setup might need
modification.
I will be happy if somebody would try this and post the result here.
Thank you,
Jan Waclawek
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