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???
06/08/11 14:57
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#182539 - I doubt it very much
Responding to: ???'s previous message
See if this code is of any help!

I doubt it very much

the OP said:
I am successfully interfaced 89C52 with 24C02, but my question is How to set communication speed ie 100 kbps.

I calculate below and have been VERY much lowballing the time for a C instruction.

Erik



#define I2C_DELAY 0x0F	                    // For delay i2c bus 

void I2C_delay(void)
{
	unsigned char i;

	for(i=0; i<I2C_DELAY; i++);
}

void I2C_clock(void)                                      60
{
	I2C_delay();

	set_scl;		// Start clock             2 

	I2C_delay();                                      60

	clr_scl;		// Clear SCL               2
}
                                                          =====
                                                          124



// this is totally unpredictable being a C delay, but I'll set it to 60 cycles

	for(i=0;i<8;i++)		//sending 8 bits of data                  say 3
	{
	 data_bit = dat & 0x80;		// Filter MSB bit keep to data_bit        say 3
	 sda = data_bit;		// Send data_bit to SDA                   say 3

	I2C_clock();      		// Call for send data to i2c bus            124  

	dat = dat<<1;                                                              say 7
	}
                                                                                  ==========
                                                                                   140


with the old steam driven uC the OP uses running at 24MHz the bit rate would be 2M/140 ~ 14kHz



List of 13 messages in thread
TopicAuthorDate
Help me ? 89C52 interfacing with EEPROM 24C02            01/01/70 00:00      
   Do *not* use 'for' loops for delays!            01/01/70 00:00      
   100k is the upper limit            01/01/70 00:00      
      HLL delay loops - just don't do it!            01/01/70 00:00      
   that may be difficult            01/01/70 00:00      
      but there is a way            01/01/70 00:00      
   See if this code is of any help!            01/01/70 00:00      
      I doubt it very much            01/01/70 00:00      
      No, it isn't            01/01/70 00:00      
   doubts 1,2,3            01/01/70 00:00      
   code for 24c02 wih 89c52            01/01/70 00:00      
      Do *not* use 'for' loops for delays!            01/01/70 00:00      
      code?            01/01/70 00:00      

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