/ **********************************************
Main chip: STC12C5A60S2 (1T)
Working frequency: 12.000MHz
*********************************************** /
#include "reg51.h"
#include "intrins.h"
TypedEfunsignedCharbyte;
TypeDefunSignedshWord;
SBITSCL = P3 ^ 4; // AT24C04 clock
SBITSDA = P3 ^ 5; // AT24C04 data
Bytebuf [16]; // data buffer area
Bytecodestdata [] =
{
0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77,
0x88, 0x99, 0xaa, 0xbb, 0xcc, 0xdd, 0xee, 0xFF
}
VoidDelay5us ();
VoidDelay5ms ();
Voidat24c04_start ();
Voidat24c04_stop ();
Voidat24c04_sendack (bitack);
Bitat24c04_recvack ();
Voidat24c04_sendbyte (bytated);
BYTEAT24C04_RECVBYTE ();
Voidat24c04_readpage ();
Voidat24c04_writepage ();
voidmain ()
{
AT24C04_WritePage ();
DELAY5MS ();
AT24C04_READPAGE ();
While (1);
}
/ **********************************************
Write 1 page (16-byte) data to AT24C04
16 test data starting with TestData, such as 00 ~ 0f address of the device
*********************************************** /
Voidat24c04_writepage ()
{
BYTEI;
AT24C04_Start (); // Start signal
AT24C04_sendByte (0xA0); // Send device address + write signal
AT24C04_sendByte (0x00); // Send storage unit address
For (i = 0; i "16; i ++)
{
BUF [I] = AT24C04_RECVBYTE ();
IF (i == 15)
{
AT24c04_sendack (1); // The last data needs NAK
}
Else
{
AT24C04_sendack (0); // Respond to ACK
}
}
AT24C04_Stop (); // Stop signal
}
/ **********************************************
Delay 5 microsecond (STC12C5A60S2 @ 12M)
Different working environments need to be adjusted to adjust this function
This delay function is calculated using a 1T instruction cycle, different from the traditional 12T MCU
*********************************************** /
void delay5us ()
{
BYTE N = 4;
While (N--)
{
_nop_();
_nop_();
}
}
/ **********************************************
Delayed 5 milliseconds (STC12C5A60S2 @ 12M)
Different working environments need to be adjusted to adjust this function
This delay function is calculated using a 1T instruction cycle, different from the traditional 12T MCU
*********************************************** /
void delay5ms ()
{
Word n = 2500;
While (N--)
{
_nop_();
_nop_();
_nop_();
_nop_();
_nop_();
}
}
/ **********************************************
Start signal
*********************************************** /
Void AT24C04_Start ()
{
SDA = 1; // pull high data cable
SCL = 1; // pull high clock line
DELAY5US (); // delay
SDA = 0; // Produce a falling edge
DELAY5US (); // delay
SCL = 0; // pull low clock line
}
/ **********************************************
Stop signal
*********************************************** /
Void AT24C04_STOP ()
{
SDA = 0; // pull low data line
SCL = 1; // pull high clock line
DELAY5US (); // delay
SDA = 1; // Produce rising edge
DELAY5US (); // delay
}
/ **********************************************
Send a response signal
Entrance parameters: ACK (0: ACK 1: NAK)
*********************************************** /
Void AT24C04_SENDACK (Bit Ack)
{
SDA = Ack; // Write acknowledge signal
SCL = 1; // pull high clock line
DELAY5US (); // delay
SCL = 0; // pull low clock line
DELAY5US (); // delay
}
/ **********************************************
Receive response signal
*********************************************** /
Bit AT24C04_RECVACK ()
{
SCL = 1; // pull high clock line
DELAY5US (); // delay
Cy = SDA; // Read response signal
SCL = 0; // pull low clock line
DELAY5US (); // delay
Return Cy;
}
/ **********************************************
Send a byte data to the IIC bus
*********************************************** /
Void AT24C04_sendByte (byte DAT)
{
BYTE I;
For (i = 0; i<8; i ++) // 8 bit counter
{
DAT << = 1; // The highest bit of the transfer
SDA = cy; // send data port
SCL = 1; // pull high clock line
DELAY5US (); // delay
SCL = 0; // pull low clock line
DELAY5US (); // delay
}
AT24C04_RECVACK ();
}
/ **********************************************
Receive one byte data from the IIC bus
*********************************************** /
BYTE AT24C04_RECVBYTE ()
{
BYTE I;
BYTE DAT = 0;
SDA = 1; // Enable internal pull-up, prepare to read data
For (i = 0; i<8; i ++) // 8 bit counter
{
DAT << = 1;
SCL = 1; // pull high clock line
DELAY5US (); // delay
DAT | = SDA; // Read data
SCL = 0; // pull low clock line
DELAY5US (); // delay
}
Return Dat;
}, Read the full text
Our other product:
