: , .. : , , , , ( ).
DS1920 (- .3-1) iN, 55 +100 0,5 0,2 . 0,5 9 , . , DS1920, . MicroLAN . .. DS1920 , .
DS1920 64- , .
8 . , , . , . 8- .
. 3-1: - DS1920
DS1920 , . 1 , , 1,55 , 3,31 . , . , , +5 . . . 3-2.
. 3-2: DS1920
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|
, .. . DS1920, MicroLAN, .
, L. , ( ). DS1920 . . , L .
DS1920 (- . 2-3). . (), , (). 55. , , , , 55, , .. 55. - . , , .
. 3-3: C DS1920
- , , , (0,5). , DS1920. 3-1 .
3-1.
, | ( ) | ( ) |
+100 | 00000000 11001000 | 00C8H |
+25 | 00000000 00110010 | 0032H |
+0.5 | 00000000 00000001 | 0001H |
00000000 00000000 | 0000H | |
-0.5 | 11111111 11111111 | FFFFH |
-25 | 11111111 11001110 | FFCEH |
-100 | 11111111 10010010 | FF92H |
, DS1920 . 0,5. TEMP_READ. , (COUNT_REMAIN). , , (COUNT_PER_C). :
T = TEMP_READ 0,25 + (COUNT_PER_C COUNT_REMAIN)/COUNT_PER_C
DS1920 , . ( 3-2): ( TH TL ). 8 . , TH TL, . . . ( ). . , , , . 8- .
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, DS192 Micro LAN 1-Wire. , 1-Wire . , , 8051 1,8 , UART 115,2 /. Micro LAN / . 0,8 (0), 2,2 (1). 2,8-6 . , , . , .
3-2.
( ) | ||
( ) | ||
TH | TH | |
TL | TL | |
COUNT REMAIN | ||
COUNT PER | ||
1-Wire . DS1920 ( . 3-4). 4 :
;
;
;
/.
. 3-4: DS1920
, ( ), , DS1920. ( 8 ). (33) 8- , 48- . , DS1920. (55) , . () . DS1920 .
(F0H) . . (). , TH TL , . 8 . (4) DS1920 , 2, .. 2 3. . , , , .
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() . (48). DS1920, . (44). , . (8) . DS1920 . , .
1. 8 2002 . ..
2. "" 2001, 2,3.
3. Dallas Semiconductor Data Book, Fall 1997
4. Atmel Corporation, Microcontroller Data Book, October 1995
5. : http://www.iButton.com, http://www.dalsemi.com, http://www.atmel.com.