Hi, I want to access the ADC0804 which is connected as the memory mapped device at 0x0001. Initially, I want check whether, address and data bus is working fine. For the same, I wrote the code as :::::Program 1::::: #include <p89v51rx2.h>
volatile unsigned char xdata *p = (char xdata *)0x0000; sbit LED = P3^0;
void main() { int j = 0;
while(1) { p[0] = 0x55; for(j=0; j<=2500; j++); LED = 0; p[1] = 0xAA; for(j = 0; j<=2500; j++); LED = 1; } }
:::::: Program 2:::::::::::::::: #include <p89v51rx2.h> #include <absacc.h>
volatile xdata at 0x1000 unsigned char config; volatile xdata at 0x1001 unsigned char config1; sbit LED = P3^0;
void main() { int j = 0; while(1) { config = 0xAA; for(j=0; j<=2500; j++); LED = 0; config1 = 0x55; for(j = 0; j<=2500; j++); LED = 1; } }
Program 1: LED Blinks but, there is no ALE or BUS transisitions. Program 2: Compiler through error that missing ; before 0x1000. This code I have refered from one of 8051 SBC webpage.
Kindly let me know what is the wrong? Is it, I need to set something in compiler? Iam using Keil uV4.
With thanks...
could not able to compile second program... The previous post was with regards to this doubt of yours.
Dont you see the difference in the definitions of the xdata variables?
volatile unsigned char xdata i _at_ 0x1000; //No compiler errors in uV4
Thanks... I will check this point. As I stated I am purly hardware engineer and this is my first programming experiance, I don't know this syntax's... I will change my code and try to check.
By the way, I am using P89V51RD2..
The IC uses 8051 architecture, hence the its only a variant from NXP having some extra features compared to the basic 8051 IC. Wont make much difference for you now.
Read the User Manual of the IC.
I am purly hardware engineer That will be helpful in understanding the IC even better and will assist you writing the code.
I am purly hardware engineer and this is my first programming experiance
trying to mak people switch to ARM, NXP has dropped "the bible" anyone know where "the bible" may still be found. It would be useful for the OP
Erik