abbreviations in program

Raj

hi

im a student doing my masters in UMIST. i am doin a project using the sx and came across a prg in which in the port assignment·some abbreviations were given they are DDIR, LVL, ST·and PLP. i don hv a clue as to what it is so if anyone can explain it to me it will be very helpful.

Thanks
Raj

Post Edited By Moderator (Chris Savage (Parallax)) : 9/3/2005 1:52:49 AM GMT

Nate

What does UMIST stand for?

Your abreviations are probably abreviations for the mode select registers (define characteristics of I/O pins):

PLP - pullup resistor (enable/disable)

ST - Schmidt Trigger (yes/no)

LVL - TTL or CMOS logic voltage level (1.3/2.5)

DDIR - Direction of edge of interrupt (low/high or high/low)?



Nate



EDIT - Chris is probably right - DDIR is most likely I/O direction.


Post Edited (Nate) : 9/3/2005 2:01:18 AM GMT

Raj

hi

thnks for replyin so quickly. UMIST is the name of the university i'm in, it is University of Manchester Institute of Science and Tech. and im doin my masters in Instrumentation and Analytical Sciences

Guenther Daubach

Raj,

I assume that these abbreviations are used in a context like

mode LVL

Somewhere in the program, or possibly in a file that is included, you should find directives like

LVL equ $0d

or

LVL = $0d

Loading the MODE register with a certain value controls which port configuration register will be accessed by subsequent

mov !R?, w

instructions. For example, to select the input voltage level registers, you would do a

mode $0d

In order to make a program more readable, you can define constants, like with LVL = $0d, and then use such constants instead of "mystic" numbers in the subsequent context, like with

mode LVL

That's all about these abbreviations.

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Greetings from Germany,

G