FIFO RAM data 8051 in C keil ?

[bianchi77]

Guys,

I have a variable like this :

unsigned char idata pat7[8] = {0xFF,0xFF,0x18,0x18,0x18,0x18,0x18,0x18,};//T
unsigned char idata pat8[8] = {0xC0,0x00,0xC0,0xC0,0xC0,0xC1,0xFE,0x3C,};//j
unsigned char idata pat9[8] = {0x18,0x18,0x00,0x18,0x18,0x18,0x18,0x18,};//i
unsigned char idata pat10[8] = {0x83,0x43,0x23,0x13,0x0F,0x13,0x23,0xC3,};//K

How can I do FIFO into RAM, so I can save memory for reusing ?

Thanks

 

[shabazmondal]

Guys,

I have a variable like this :

unsigned char idata pat7[8] = {0xFF,0xFF,0x18,0x18,0x18,0x18,0x18,0x18,};//T
unsigned char idata pat8[8] = {0xC0,0x00,0xC0,0xC0,0xC0,0xC1,0xFE,0x3C,};//j
unsigned char idata pat9[8] = {0x18,0x18,0x00,0x18,0x18,0x18,0x18,0x18,};//i
unsigned char idata pat10[8] = {0x83,0x43,0x23,0x13,0x0F,0x13,0x23,0xC3,};//K

How can I do FIFO into RAM, so I can save memory for reusing ?

Thanks

Have a pointer pointed at the last location i.e. 8.
now u can access any of the data, copy it in a location and decrement the counter.
have a different pointer for each one of the array

 

[bianchi77]

Have a pointer pointed at the last location i.e. 8.
now u can access any of the data, copy it in a location and decrement the counter.
have a different pointer for each one of the array

Can you give me one example of pointer ?

For example I have :

unsigned char idata pat10[8] = {0x83,0x43,0x23,0x13,0x0F,0x13,0x23,0xC3,};//K

And then ?
unsigned char idata pat10[8] = {0x83,0x43,0x23,0x13,0x0F,0x13,0x23,0xC3,};//K ??
i[1] = pat10[0,8] ??
x = i[1];
for (x=8;x=0;x--);

 

[shabazmondal]

Can you give me one example of pointer ?

For example I have :


And then ?
unsigned char idata pat10[8] = {0x83,0x43,0x23,0x13,0x0F,0x13,0x23,0xC3,};//K ??
i[1] = pat10[0,8] ??
x = i[1];
for (x=8;x=0;x--);

unsigned char idata pat10[8] = {0x83,0x43,0x23,0x13,0x0F,0x13,0x23,0xC3,};//this is correct

now imagine u want to take out 2 bytes of data at every instance an place it in 2 different variables 'a' and 'b' to use them somewhere.

x=8;
a=pat10[x]; // a gets the data 0xC3 and pointer is at 8th location
//now if u want to put remove data from 7th location,
x--; // pointer pointing at 7th location
b=pat10[x];


if you need to do it again and again for a specific function you can use the for loop in a desired manner decrementing or incrementing x as and when you take data or put in data

Hope you have understood

 

[bianchi77]

unsigned char idata pat10[8] = {0x83,0x43,0x23,0x13,0x0F,0x13,0x23,0xC3,};//this is correct

now imagine u want to take out 2 bytes of data at every instance an place it in 2 different variables 'a' and 'b' to use them somewhere.

x=8;
a=pat10[x]; // a gets the data 0xC3 and pointer is at 8th location
//now if u want to put remove data from 7th location,
x--; // pointer pointing at 7th location
b=pat10[x];


if you need to do it again and again for a specific function you can use the for loop in a desired manner decrementing or incrementing x as and when you take data or put in data

Hope you have understood

for(x=8;x=0;x--)
{
a=pat10[x]; // a gets the data 0xC3 and pointer is at 8th location
}

how can I put 'b' variable in that loop ?
a will be =
a = pat10[8] until....a = pat10[1], right ?

Thanks

 

[shabazmondal]

for(x=8;x=0;x--)
{
a=pat10[x]; // a gets the data 0xC3 and pointer is at 8th location
}

how can I put 'b' variable in that loop ?
a will be =
a = pat10[8] until....a = pat10[1], right ?

Thanks

to put the b variable u can do this
for(x=8;x=0;x--)
{
a=pat10[x]; // a gets the data 0xC3 and pointer is at 8th location
x--;
b=pat10[x];// b gets the data of the 7th location,and in the next round a will get the data of the 6th location.
}

 

[bianchi77]

to put the b variable u can do this
for(x=8;x=0;x--)
{
a=pat10[x]; // a gets the data 0xC3 and pointer is at 8th location
x--;
b=pat10[x];// b gets the data of the 7th location,and in the next round a will get the data of the 6th location.
}

I see, that does the trick doesn't it
Thanks

---------- Post added at 23:26 ---------- Previous post was at 23:16 ----------

if I have pat0 until pat25 ?
for example :

.
.
unsigned char idata pat7[8] = {0xFF,0xFF,0x18,0x18,0x18,0x18,0x18,0x18,};
unsigned char idata pat8[8] = {0xC0,0x00,0xC0,0xC0,0xC0,0xC1,0xFE,0x3C,};
.
.

How can I do FIFO ? create function and do one by one ?

Thank you my friend

 

[shabazmondal]

i didnt get ur question..
do you want to extract the data from each and every array like..if u want data of 8th position u take all the data together from all arrays???

 

[bianchi77]

i didnt get ur question..
do you want to extract the data from each and every array like..if u want data of 8th position u take all the data together from all arrays???

I want to save memory RAM, do you know how to save memory with FIFO ?

 

[shabazmondal]

I want to save memory RAM, do you know how to save memory with FIFO ?

If you can provide me with some more information then I may help you with this

 

[bianchi77]

If you can provide me with some more information then I may help you with this

I want to display a pattern in a loop but run out of memory,

unsigned char idata pat7[8] = {0xFF,0xFF,0x18,0x18,0x18,0x18,0x18,0x18,};
unsigned char idata pat8[8] = {0xC0,0x00,0xC0,0xC0,0xC0,0xC1,0xFE,0x3C,};
.
.


void display(unsigned char pattern[])//, int num)
{
unsigned int cnt, col, row; //, num ;


row = 1;
//for (cnt = num*8 ; cnt < (num*8+8) ; cnt ++ ) //display pattern each character
for (cnt = 0 ; cnt < 8 ; cnt ++ ) //display pattern each character
{
P3 = ~pattern[cnt];
P1 = ~row;

delay_ms(30) ; // delay of 1 ms
row = row<<1;


}

row = 0x00;

display(pat7);
.
.
}

how can I use FIFO for this case ?

Thanks

 

[FvM]

I don't see the purpose of a FIFO in the present case. You'll preferably define patx[] arays as constant (ROM) data and supply a ROM (code) pointer to the display function.

 

[bianchi77]

I don't see the purpose of a FIFO in the present case. You'll preferably define patx[] arays as constant (ROM) data and supply a ROM (code) pointer to the display function.

how can I define those patterns in RAM and do FIFO ?

Thanks

 

[shabazmondal]

how can I define those patterns in RAM and do FIFO ?

Thanks

As FvM said...even i dont think u need to save memory...as u have already allocated that memory space..

 

[FvM]

An example with the character generator tables in ROM. Of course you can place in idata, if it has to be loaded at run-time. But usually, it won't, I presume.

unsigned char code pat7[8] = {0xFF,0xFF,0x18,0x18,0x18,0x18,0x18,0x18,};
unsigned char code pat8[8] = {0xC0,0x00,0xC0,0xC0,0xC0,0xC1,0xFE,0x3C,};

unsigned char code *pp;
unsigned char a;

pp = &pat7[7];

for (i=0;i<8;i++)
  a = *pp--;