Mercurial > public > mk2
annotate code_part1/OSTC_code_asm_part1/i2c_eeprom.asm @ 214:8a0bbe43df65
(altimeter restart: fix bank addressing)
author | JeanDo |
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date | Wed, 23 Feb 2011 00:53:56 +0100 |
parents | 055977afc2f9 |
children | dee88c962653 |
rev | line source |
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0 | 1 |
2 ; OSTC - diving computer code | |
3 ; Copyright (C) 2008 HeinrichsWeikamp GbR | |
4 ; This program is free software: you can redistribute it and/or modify | |
5 ; it under the terms of the GNU General Public License as published by | |
6 ; the Free Software Foundation, either version 3 of the License, or | |
7 ; (at your option) any later version. | |
8 ; This program is distributed in the hope that it will be useful, | |
9 ; but WITHOUT ANY WARRANTY; without even the implied warranty of | |
10 ; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
11 ; GNU General Public License for more details. | |
12 ; You should have received a copy of the GNU General Public License | |
13 ; along with this program. If not, see <http://www.gnu.org/licenses/>. | |
14 ; provides routines for external EEPROM via I2C | |
15 ; written by: Matthias Heinrichs, info@heinrichsweikamp.com | |
16 ; written: 10/30/05 | |
17 ; last updated: 08/21/06 | |
18 ; known bugs: | |
19 ; ToDo: use 2nd 32KB from external EEPROM for something | |
20 | |
21 incf_eeprom_address macro ext_ee_temp1 ; Will increase eeprom_address:2 with the 8Bit value "ext_ee_temp1" and takes | |
148 | 22 movlw ext_ee_temp1 ; care of bank switching at 0x8000 |
23 call incf_eeprom_address0 | |
0 | 24 endm |
25 | |
26 incf_eeprom_address0: | |
148 | 27 addwf eeprom_address+0,F ; increase address |
28 movlw d'0' | |
29 addwfc eeprom_address+1,F | |
0 | 30 |
148 | 31 btfss eeprom_address+1,7 ; at address 8000? |
32 return ; No, continue | |
33 | |
34 ; Yes, clear eeprom_address:2 | |
35 clrf eeprom_address+0 ; Clear eeprom address | |
36 clrf eeprom_address+1 | |
37 return ; Done. | |
38 | |
39 ;============================================================================= | |
40 ; Will decrease eeprom_address:2 with the 8Bit value "ext_ee_temp1" and takes | |
41 ; care of bank switching at 0x8000 | |
42 | |
43 decf_eeprom_address macro ext_ee_temp1 | |
44 movlw ext_ee_temp1 | |
45 call decf_eeprom_address0 | |
46 endm | |
0 | 47 |
48 decf_eeprom_address0: | |
148 | 49 subwf eeprom_address+0,F ; decrease address: do a 16-8bits substract. |
50 movlw d'0' | |
51 subwfb eeprom_address+1,F | |
0 | 52 |
148 | 53 btfss eeprom_address+1,7 ; at address 8000? |
54 return ; No, done. | |
0 | 55 |
148 | 56 movlw b'01111111' ; yes, reset highbyte |
57 movwf eeprom_address+1 | |
58 return ; Done. | |
59 | |
60 ;============================================================================= | |
0 | 61 |
62 write_external_eeprom: ; data in WREG | |
63 ; increase address eeprom_address+0:eeprom_address+1 after write | |
64 ; with banking after 7FFF | |
81
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65 #ifdef TESTING |
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66 ; When Simulating with MPLabSIM, there is no way to emulate external EEPROM... |
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67 return |
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68 #endif |
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69 |
0 | 70 rcall I2CWRITE ; writes WREG into EEPROM@eeprom_address |
71 movlw d'1' ; increase address | |
72 addwf eeprom_address+0,F | |
73 movlw d'0' | |
74 addwfc eeprom_address+1,F | |
75 bcf eeprom_overflow | |
76 btfss eeprom_address+1,7 ; at address 8000? | |
77 return ; no, return | |
78 | |
79 clrf eeprom_address+0 ; Clear eeprom address | |
80 clrf eeprom_address+1 | |
81 bsf eeprom_overflow ; and set overflow bit | |
82 return | |
83
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83 |
0 | 84 write_external_eeprom_block: ; Writes a block of 64Byte (one page in external EEPROM without stop condition |
81
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85 #ifdef TESTING |
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86 ; When Simulating with MPLabSIM, there is no way to emulate external EEPROM... |
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87 return |
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88 #endif |
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89 |
0 | 90 btfsc eeprom_blockwrite ; Blockwrite continue? |
91 rcall I2CWRITE_BLOCK2 | |
92 btfss eeprom_blockwrite ; Blockwrite start? | |
93 rcall I2CWRITE_BLOCK | |
94 bsf eeprom_blockwrite ; After the start, do blockwriting for the next 63Bytes! | |
95 | |
96 movlw d'0' ; increase address | |
97 incf eeprom_address+0,F | |
98 addwfc eeprom_address+1,F | |
99 bcf eeprom_overflow | |
100 | |
101 btfss eeprom_address+1,7 ; at address 8000 | |
102 return ; no, return | |
103 | |
104 clrf eeprom_address+0 ; Clear eeprom address | |
105 clrf eeprom_address+1 | |
106 bsf eeprom_overflow ; and set overflow bit | |
107 return | |
108 I2CWRITE_BLOCK: | |
109 movwf ext_ee_temp1 ; Data byte in WREG | |
110 bsf SSPCON2,SEN ; Start condition | |
111 rcall WaitMSSP | |
112 movlw b'10100110' ; Bit0=0: WRITE, Bit0=1: READ | |
113 movwf SSPBUF ; control byte | |
114 rcall WaitMSSP | |
115 rcall I2C_WaitforACK | |
116 movff eeprom_address+1,SSPBUF ; High Address byte | |
117 rcall WaitMSSP | |
118 rcall I2C_WaitforACK | |
119 movff eeprom_address+0,SSPBUF ; Low Address byte | |
120 rcall WaitMSSP | |
121 rcall I2C_WaitforACK | |
122 I2CWRITE_BLOCK2: | |
123 movff ext_ee_temp1, SSPBUF ; Data Byte | |
124 rcall WaitMSSP | |
125 rcall I2C_WaitforACK | |
126 return | |
127 | |
128 | |
129 get_free_EEPROM_location: ; Searches 0xFD, 0xFD, 0xFE and sets Pointer to 0xFE | |
81
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130 |
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131 #ifdef TESTING |
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132 ; In testing mode, find 0x100 (internal EEPROM) as the first free location... |
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133 clrf eeprom_address+0 ; Not found in entire EEPROM, set to address 0 |
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134 movlw 0x1 |
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135 movwf eeprom_address+1 |
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136 return |
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137 #endif |
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138 |
0 | 139 clrf ext_ee_temp1 ; low address counter |
140 clrf ext_ee_temp2 ; high address counter | |
141 bcf second_FD ; clear flags | |
142 bcf first_FD | |
143 get_free_EEPROM_location3: | |
144 bsf SSPCON2, PEN ; Stop condition | |
145 rcall WaitMSSP | |
146 bsf SSPCON2,SEN ; Start condition | |
147 rcall WaitMSSP | |
148 movlw b'10100110' ; Bit0=0: WRITE, Bit0=1: READ | |
149 movwf SSPBUF ; control byte | |
150 rcall WaitMSSP | |
151 btfsc SSPCON2,ACKSTAT | |
152 bra get_free_EEPROM_location3 ; EEPROM NOT acknowledged, retry! | |
153 | |
154 movff ext_ee_temp2,SSPBUF ; High Address byte | |
155 rcall WaitMSSP | |
156 rcall I2C_WaitforACK | |
157 movff ext_ee_temp1,SSPBUF ; Low Address byte | |
158 rcall WaitMSSP | |
159 rcall I2C_WaitforACK | |
160 | |
161 bsf SSPCON2,RSEN ; Start condition | |
162 rcall WaitMSSP | |
163 movlw b'10100111' ; Bit0=0: WRITE, Bit0=1: READ | |
164 movwf SSPBUF ; control byte | |
165 rcall WaitMSSP | |
166 rcall I2C_WaitforACK | |
167 | |
168 get_free_EEPROM_location2: | |
169 bsf SSPCON2, RCEN ; Enable recieve mode | |
170 rcall WaitMSSP | |
171 btfsc first_FD | |
172 bra test_2nd_FD | |
173 bsf first_FD ; found first 0xFD? | |
174 movlw 0xFD | |
175 cpfseq SSPBUF | |
176 bcf first_FD ; No | |
177 bra get_free_EEPROM_location2c | |
178 | |
179 test_2nd_FD: | |
180 btfsc second_FD | |
181 bra test_FE | |
182 bsf second_FD ; found second 0xFD? | |
183 movlw 0xFD | |
184 cpfseq SSPBUF | |
185 bra get_free_EEPROM_location2b ;No, clear both flags | |
186 bra get_free_EEPROM_location2c | |
187 test_FE: | |
188 movlw 0xFE ; found the final 0xFE? | |
189 cpfseq SSPBUF | |
190 bra get_free_EEPROM_location2b ;No, clear both flags | |
191 movff ext_ee_temp1,eeprom_address+0 ;Yes, copy ext_ee_temp1->eeprom_address+0 and | |
192 movff ext_ee_temp2,eeprom_address+1 ;ext_ee_temp2->eeprom_address+1 | |
193 bra get_free_EEPROM_location4 ; Done. | |
194 | |
195 get_free_EEPROM_location2b: | |
196 bcf second_FD ; clear both flags! | |
197 bcf first_FD | |
198 get_free_EEPROM_location2c: | |
199 movlw d'1' ; and increase search address | |
200 addwf ext_ee_temp1,F | |
201 movlw d'0' | |
202 addwfc ext_ee_temp2,F | |
203 | |
42 | 204 btfsc ext_ee_temp2,7 ; 0x8000 reached? |
0 | 205 bra get_free_EEPROM_location3b ; yes |
206 | |
207 bsf SSPCON2, ACKEN ; no, send Ack | |
208 rcall WaitMSSP | |
209 bra get_free_EEPROM_location2 ; and continue search | |
210 get_free_EEPROM_location3b: | |
211 clrf eeprom_address+0 ; Not found in entire EEPROM, set to address 0 | |
212 clrf eeprom_address+1 | |
213 get_free_EEPROM_location4: | |
214 bsf SSPCON2, PEN ; Stop | |
215 rcall WaitMSSP | |
216 | |
217 bcf second_FD ; clear flags | |
218 bcf first_FD | |
219 return ; return | |
220 | |
221 | |
222 I2CREAD: | |
223 bsf SSPCON2, PEN ; Stop | |
224 rcall WaitMSSP | |
225 bsf SSPCON2,SEN ; Start condition | |
226 rcall WaitMSSP | |
227 movlw b'10100110' ; Bit0=0: WRITE, Bit0=1: READ | |
228 movwf SSPBUF ; control byte | |
229 rcall WaitMSSP | |
230 btfsc SSPCON2,ACKSTAT | |
231 bra I2CREAD ; EEPROM NOT acknowledged, retry! | |
232 movff eeprom_address+1,SSPBUF ; High Address byte | |
233 rcall WaitMSSP | |
234 rcall I2C_WaitforACK | |
235 movff eeprom_address+0,SSPBUF ; Low Address byte | |
236 rcall WaitMSSP | |
237 rcall I2C_WaitforACK | |
238 | |
239 bsf SSPCON2,RSEN ; Start condition | |
240 rcall WaitMSSP | |
241 movlw b'10100111' ; Bit0=0: WRITE, Bit0=1: READ | |
242 movwf SSPBUF ; control byte | |
243 rcall WaitMSSP | |
244 rcall I2C_WaitforACK | |
245 | |
246 bsf SSPCON2, RCEN ; Enable recieve mode | |
247 rcall WaitMSSP | |
248 movf SSPBUF,W ; copy read byte into WREG | |
249 bsf SSPCON2, PEN ; Stop | |
250 rcall WaitMSSP | |
251 return | |
252 | |
253 I2CREAD2: ; same as I2CREAD but with automatic address increase | |
254 rcall I2CREAD | |
255 movlw d'1' | |
256 addwf eeprom_address+0,F | |
257 movlw d'0' | |
258 addwfc eeprom_address+1,F | |
259 bcf eeprom_overflow | |
260 btfss eeprom_address+1,7 ; at 0x8000? | |
261 return ; no, return | |
262 | |
263 clrf eeprom_address+0 ; Yes, clear address | |
264 clrf eeprom_address+1 | |
265 bsf eeprom_overflow ; and set overflow bit | |
266 return | |
267 | |
268 I2CWRITE: | |
269 movwf ext_ee_temp1 ; Data byte | |
270 bsf SSPCON2,SEN ; Start condition | |
271 rcall WaitMSSP | |
272 movlw b'10100110' ; Bit0=0: WRITE, Bit0=1: READ | |
273 movwf SSPBUF ; control byte | |
274 rcall WaitMSSP | |
275 rcall I2C_WaitforACK | |
276 movff eeprom_address+1,SSPBUF ; High Address byte | |
277 rcall WaitMSSP | |
278 rcall I2C_WaitforACK | |
279 movff eeprom_address+0,SSPBUF ; Low Address byte | |
280 rcall WaitMSSP | |
281 rcall I2C_WaitforACK | |
282 movff ext_ee_temp1, SSPBUF ; Data Byte | |
283 rcall WaitMSSP | |
284 rcall I2C_WaitforACK | |
285 bsf SSPCON2,PEN ; Stop condition | |
286 rcall WaitMSSP | |
287 WAITMS d'6' ; Write delay | |
288 return | |
289 | |
290 I2C_WaitforACK: | |
291 btfsc SSPCON2,ACKSTAT ; checks for ACK bit from slave | |
292 rcall I2CFail | |
293 return | |
294 | |
295 I2CFail: | |
296 ostc_debug 'M' ; Sends debug-information to screen if debugmode active | |
21 | 297 bsf LED_red |
0 | 298 rcall I2CReset ; I2C Reset |
299 bcf PIR1,SSPIF | |
300 clrf i2c_temp | |
301 return | |
302 | |
303 WaitMSSP: | |
304 decfsz i2c_temp,F ; check for timeout during I2C action | |
305 bra WaitMSSP2 | |
306 bra I2CFail ; timeout occured | |
307 WaitMSSP2: | |
308 btfss PIR1,SSPIF | |
309 bra WaitMSSP | |
310 clrf i2c_temp | |
311 bcf PIR1,SSPIF | |
312 return | |
313 | |
314 I2CReset: ; Something went wrong (Slave holds SDA low?) | |
315 clrf SSPCON1 ; wake-up slave and reset entire module | |
316 ostc_debug 'N' ; Sends debug-information to screen if debugmode active | |
317 clrf SSPCON2 | |
318 clrf SSPSTAT | |
319 bcf TRISC,3 ; SCL OUTPUT | |
320 bsf TRISC,4 ; SDA Input | |
321 bcf PORTC,3 | |
322 movlw d'9' | |
323 movwf i2c_temp ; clock-out 9 clock cycles manually | |
324 I2CReset_1: | |
325 bsf PORTC,3 ; SCL=1 | |
326 nop | |
327 btfsc PORTC,4 ; SDA=1? | |
328 bra I2CReset_2 ; =1, SDA has been released from slave | |
329 bcf PORTC,3 ; SCL=0 | |
330 bcf PORTC,3 | |
331 decfsz i2c_temp,F | |
332 bra I2CReset_1 ; check for nine clock cycles | |
333 I2CReset_2: | |
334 bsf TRISC,3 ; SCL Input | |
335 clrf SSPCON1 ; set I²C Mode | |
336 WAITMS d'10' ; Reset-Timeout for I2C devices | |
337 movlw b'00000000' | |
338 movwf SSPSTAT | |
339 movlw b'00101000' | |
340 movwf SSPCON1 | |
341 movlw b'00000000' | |
342 movwf SSPCON2 | |
343 movlw d'8' ; 400kHz I2C clock @ 16MHz Fcy | |
344 movwf SSPADD | |
21 | 345 bcf LED_red |
0 | 346 ostc_debug 'O' ; Sends debug-information to screen if debugmode active |
347 return | |
53 | 348 |
349 ;I2C_TX: | |
350 ; movwf i2c_temp2 ; Data byte | |
351 ; bsf SSPCON2,SEN ; Start condition | |
352 ; rcall WaitMSSP | |
353 ; movlw b'10010000' ; Bit0=0: WRITE, Bit0=1: READ | |
354 ; movwf SSPBUF ; control byte | |
355 ; rcall WaitMSSP | |
356 ; rcall I2C_WaitforACK | |
357 ; movff i2c_temp2, SSPBUF ; Data Byte | |
358 ; rcall WaitMSSP | |
359 ; rcall I2C_WaitforACK | |
360 ; bsf SSPCON2,PEN ; Stop condition | |
361 ; rcall WaitMSSP | |
362 ; return | |
363 ;I2C_RX: | |
364 ; bcf PIR1,SSPIF | |
365 ; bsf SSPCON2,SEN ; Start condition | |
366 ; rcall WaitMSSP | |
367 ; movlw b'10010001' ; Bit0=0: WRITE, Bit0=1: READ | |
368 ; movwf SSPBUF ; control byte | |
369 ; rcall WaitMSSP | |
370 ; rcall I2C_WaitforACK | |
371 ; bsf SSPCON2, RCEN ; Enable recieve mode | |
372 ; rcall WaitMSSP | |
373 ; movff SSPBUF,i2c_temp2 ; Data Byte | |
374 ; bsf SSPCON2,ACKEN ; Master acknowlegde | |
375 ; rcall WaitMSSP | |
376 ; bsf SSPCON2,PEN ; Stop condition | |
377 ; rcall WaitMSSP | |
378 ; return |