Hi All, Could some one please help me out in the way as to how to read from a 1024K mem. I am using 512K at the present moment using the operation below.
do{ GoMaster(addr); // set address if(NoAck==1)SendStop(); // if no acknowledge, end transaction }while (NoAck==1); SendByte((b_num & 0xff00)>>8); SendByte((b_num & 0x00ff)); SendByte(dat); SendStop();
It would be helpful if you provided part number of the memory IC you are using. If it is Microchip's 24xx1025, then the most significant bit of the address is encoded in the I2C address byte, also known as the control byte in Microchip's docs. Regards, - mike
Hi Mike, I am using AT24C1024 IC. I am also having trouble in the use of P0 as MSB in device word address. in AT24C512 which i am using A0 and A1 which tell me that i can use 4 devices. Here i know that only two ICs can be connected using A1. But what is the use of P0 here? thank you ajay
A quote from the datasheet for AT24C1024: The seventh bit (P0) of the device address is a memory page address bit. This memory page address bit is the most significant bit of the data word address that follows. Seems clear to me. It appears that P0 is the most significant bit of the 17-bit address. Regards, - mike
Hi Mike, I had understood that but what i did not know was where to send it. But I found that out from some article that it is to be sent along with the 8 bit address word which contains A1 and then the rest of the sixteen bits as normal in 512. Thank you for your help Ajay
You should extract the 17th bit of the address, place it in the P0 and send it along with the (address + R/W) byte. For ex, assume the device address bit A1=1. if the address of the EEPROM to read is 0x10000, then the very first byte you supposed to send after generating a START is '10100111'(i.e. 0xA7) - Neo
Hi Neo, Thank you for that, I will do that and try it out. Thank you Ajay