Please help in programming EEPROM.

[nikhildascl]

I've written the code for EEPROM with 89c52. But it is not working. My code is given below. Please help...

		ORG 00H
SDA EQU P1.4
SCL EQU P1.5
        	
;I2C
		LCALL I2C_START
		MOV A,0xA0
		LCALL I2C_SEND
		LCALL ACK
		MOV A,0x01
		LCALL I2C_SEND
		LCALL ACK
		MOV A,#3FH		; send 3Fh
		LCALL I2C_SEND
		LCALL ACK
		LCALL I2C_STOP
		CLR P2.0
		LCALL DELAY
		;................
		LCALL I2C_START
		MOV A,0xA0
		LCALL I2C_SEND
		LCALL ACK
		MOV A,0x10
		LCALL I2C_SEND
		LCALL ACK
		MOV A,0xA1
		LCALL I2C_SEND
		LCALL ACK
		MOV A,0x00
		LCALL I2C_SEND
		LCALL ACK
		LCALL I2C_STOP
AGAIN:	SJMP AGAIN


;I2C START


I2C_START:
		SETB SDA
		LCALL DELAY
		SETB SCL
		LCALL DELAY
		CLR SDA
		LCALL DELAY
		CLR SCL
		LCALL DELAY
	    RET
;I2C STOP


I2C_STOP:
		CLR SDA
		LCALL DELAY
		SETB SCL
		LCALL DELAY
		SETB SDA
		LCALL DELAY
		CLR SCL
		LCALL DELAY
		RET
;I2C SEND BYTE


I2C_SEND:
		RLC A
		MOV SDA,C
		LCALL DELAY
		SETB SCL
		LCALL DELAY
		CLR SCL
		LCALL DELAY
		RET
;I2C RECEIVE BYTE


I2C_READ:
		SETB SDA
		LCALL DELAY
		SETB SCL
		MOVC A,@A+DPTR
		LCALL DELAY
		CLR SCL
		CLR SDA
		RET


;ACKNOWLEDGE


ACK:	
		SETB SCL
		LCALL DELAY
		LCALL DELAY
		CLR SCL
		RET	
; DELAY PROGRAM
DELAY:	
		MOV R3,#255
HERE:	MOV R4,#255
HERE2:	DJNZ R2,HERE2
		DJNZ R1,HERE
		RET

 

[srizbf]

in your delay code, you are initialising R3 and R4.
but decrementing R2 and R1.
so it should be:

; DELAY PROGRAM
DELAY:	
		MOV R2,#255
HERE:	MOV R1,#255
HERE2:	DJNZ R2,HERE2
		DJNZ R1,HERE
		RET

---------- Post added at 09:17 ---------- Previous post was at 09:16 ----------

did you calculated the delay ? it will be very high?

 

[nikhildascl]

Sorry. But now there is no problem with delay. Still the programs is not working. Is there any mistake with the I2C program??

 

[srizbf]

[

use the delay code alone in a test routine and find/monitor with scope , the delay value.

 

[FvM]

Assuming your 805a works at 12 MHz and the EEPROM supports 400 kHz I2C operation, a single NOP delay would be sufficient to achieve a legal timing.

As an obvious fault, the send and receive routines are missing a loop over 8 bits. There may be more errors.

Why don't you refer to a known working I2C code for 8051?

 

[nikhildascl]

I didnt get a working code...

 

[srizbf]

I didnt get a working code...

attached here is the i2c code for 8051.

 

[Arch Zone]

what EEPROM type do you use? how do you connect address selector pin? I see you only send one bit at your i2c_send and i2c_read, it need 8-bit to be sent.

 

[nikhildascl]

Actually i dont know about this. Plz help...

 

[Arch Zone]

I mean, is that 24C04, 24C08, 24C16 or what?
>different type needs different program.
how much size (Byte) do you need, do you want to use all of it's capacity?
How you connect pin 1, 2, 3?
>if you just want to use less then 256 bytes, you can connect pin 1, 2, 3 directly to ground. It will make you understand the concept easier.

Of course, we will help you.

And Also i saw you wrote Mov A,0x0A
I don't know what your compiler specification. For my compiler, Mov A,0Ah will store SFR data located at 0Ah to accomulator. You must use Mov A,#0Ah or maybe Mov A,#0x0A.

 

[moha1106]

I mean, is that 24C04, 24C08, 24C16 or what?
>different type needs different program.
how much size (Byte) do you need, do you want to use all of it's capacity?
How you connect pin 1, 2, 3?
>if you just want to use less then 256 bytes, you can connect pin 1, 2, 3 directly to ground. It will make you understand the concept easier.

Of course, we will help you.

And Also i saw you wrote Mov A,0x0A
I don't know what your compiler specification. For my compiler, Mov A,0Ah will store SFR data located at 0Ah to accomulator. You must use Mov A,#0Ah or maybe Mov A,#0x0A.

Suppose i want to use more than 256 bytes then how i can connect a0,a1,a2 pins... i m in urgent need...

 

[Arch Zone]

If you use 24CXX family, connect A0, A1, A2 to uC's ports. But, as i asked before, what EEPROM type do you use? It's important. Now, there are many families and types of EEPROM in the market, and each needs special way.

i m in urgent need...

Unfortunately, i'm also in busy right now, i don't know when i can and will be sign in again. I hope, friends here want to help you, or just use EEPROM type and code that i already posted for you on your another thread. Good luck.