?? 26.lst
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160 // I2C Peripheral Function Prototypes
161 //------------------------------------------------------------------------------
162
163 //------------------------------------------------------------------------------
164 // Procedure: write_byte
165 // Inputs: data out, address
166 // Outputs: none
167 // Description: Writes a byte to the EEPROM given the address
168 //------------------------------------------------------------------------------
169 void write_byte (unsigned char data_out, unsigned int address)
170 {
171 1 i2c_start(); // Send start signal
172 1 i2c_write(0xA0); // Send identifier I2C address
173 1 i2c_write(high_byte(address)); // Send address to EEPROM
174 1 i2c_write((unsigned char)address); // Send address to EEPROM
175 1 i2c_stop_and_write(data_out); // Send low byte to EEPROM
176 1 delay_time(DELAY_WRITE); // Delay a period of time to write
177 1 }
178
179 //------------------------------------------------------------------------------
C51 COMPILER V7.09 26 03/22/2005 10:03:29 PAGE 4
180 // Procedure: read_byte
181 // Inputs: address
182 // Outputs: none
183 // Description: Reads a byte from the EEPROM given the address
184 //------------------------------------------------------------------------------
185 unsigned char read_byte (unsigned int address)
186 {
187 1 unsigned char data_in;
188 1
189 1 i2c_start(); // Send start signal
190 1 i2c_write(0xA0); // Send identifer I2C address
191 1 i2c_write(high_byte(address)); // Send address to EEPROM
192 1 // Send address to EEPROM
193 1 // Send repeated start signal
194 1 repeated_i2c_start_and_write((unsigned char)address);
195 1
196 1 i2c_write(0xA1); // Send identifer I2C address
197 1 data_in = i2c_stop_and_read(); // Read byte, send stop signal
198 1
199 1 return data_in;
200 1 }
201
202
203 //------------------------------------------------------------------------------
204 // Routine: i2c_start
205 // Inputs: none
206 // Outputs: none
207 // Purpose: Sends I2C Start Trasfer - State "B"
208 //------------------------------------------------------------------------------
209 void i2c_start (void)
210 {
211 1 while (BUS_BUSY); // Wait until we are clear to write
212 1 BUS_START = TRUE; // Perform I2C start
213 1 while (!BUS_INT); // Wait until start sent
214 1 BUS_START = FALSE; // Reset I2C start
215 1 BUS_INT = 0; // Clear SI
216 1 }
217
218 //------------------------------------------------------------------------------
219 // Routine: repeated_i2c_start_and_write
220 // Inputs: none
221 // Outputs: none
222 // Purpose: Sends I2C Start Trasfer - State "B"
223 //------------------------------------------------------------------------------
224 void repeated_i2c_start_and_write (unsigned char output_data)
225 {
226 1 BUS_START = TRUE; // Perform I2C start
227 1 SMB0DAT = output_data; // Put data into buffer
228 1 while (!BUS_INT); // Wait unitl we are done with send
229 1 BUS_INT = 0; // Clear SI
230 1 BUS_START = FALSE; // Reset I2C start
231 1 while (!BUS_INT); // Wait unitl we are done with reset
232 1 BUS_INT = 0; // Clear SI
233 1 }
234
235 //------------------------------------------------------------------------------
236 // Routine: i2c_stop_and_write
237 // Inputs: output byte
238 // Outputs: none
239 // Purpose: Sends I2C Stop Trasfer - State "C" (also sends last byte)
240 //------------------------------------------------------------------------------
241 void i2c_stop_and_write (unsigned char output_data)
C51 COMPILER V7.09 26 03/22/2005 10:03:29 PAGE 5
242 {
243 1 BUS_STOP = TRUE; // Perform I2C stop
244 1 SMB0DAT = output_data; // Put data into buffer
245 1 while (!BUS_INT); // Wait unitl we are done with send
246 1 BUS_INT = 0; // Clear SI
247 1 }
248
249 //------------------------------------------------------------------------------
250 // Routine: i2c_stop_and_read
251 // Inputs: none
252 // Outputs: input byte
253 // Purpose: Sends I2C Stop Trasfer - State "C" (also reads last byte)
254 //------------------------------------------------------------------------------
255 unsigned char i2c_stop_and_read (void)
256 {
257 1 unsigned char input_data;
258 1
259 1 BUS_STOP = TRUE; // Perform I2C stop
260 1 while (!BUS_INT); // Wait until we have data to read
261 1 input_data = SMB0DAT; // Read the data
262 1 BUS_INT = 0; // Clear SI
263 1
264 1 return input_data;
265 1 }
266
267 //------------------------------------------------------------------------------
268 // Routine: i2c_write
269 // Inputs: output byte
270 // Outputs: none
271 // Purpose: Writes data over the I2C bus
272 //------------------------------------------------------------------------------
273 void i2c_write (unsigned char output_data)
274 {
275 1 SMB0DAT = output_data; // Put data into buffer
276 1 while (!BUS_INT); // Wait unitl we are done with send
277 1 BUS_INT = 0; // Clear SI
278 1 }
279
280 //------------------------------------------------------------------------------
281 // Routine: i2c_read
282 // Inputs: none
283 // Outputs: input byte
284 // Purpose: Reads data from the I2C bus
285 //------------------------------------------------------------------------------
286 unsigned char i2c_read (void)
287 {
288 1 unsigned char input_data;
289 1
290 1 while (!BUS_INT); // Wait until we have data to read
291 1 input_data = SMB0DAT; // Read the data
292 1 BUS_INT = 0; // Clear SI
293 1
294 1 return input_data;
295 1 }
296
297
298
299 ////////////////////////////////////////////////////////////////////////////////
300 // Routine: delay_time
301 // Inputs: counter value to stop delaying
302 // Outputs: none
303 // Purpose: To pause execution for pre-determined time
C51 COMPILER V7.09 26 03/22/2005 10:03:29 PAGE 6
304 ////////////////////////////////////////////////////////////////////////////////
305 void delay_time (unsigned int time_end)
306 {
307 1 unsigned int index;
308 1 for (index = 0; index < time_end; index++);
309 1 }
MODULE INFORMATION: STATIC OVERLAYABLE
CODE SIZE = 366 ----
CONSTANT SIZE = 208 ----
XDATA SIZE = ---- ----
PDATA SIZE = ---- ----
DATA SIZE = ---- 8
IDATA SIZE = ---- ----
BIT SIZE = ---- ----
END OF MODULE INFORMATION.
C51 COMPILATION COMPLETE. 0 WARNING(S), 0 ERROR(S)
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