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chao ban,
BCD uses 4 binary bits to encode each decimal digit. Vi' du. la: ban muon dua du lieu ngay 27 vao trong con IC, thi ban phai dung 0x27, chung khong phai la 0x1B. 0x1B la sai roi, khong phai la ngay 27 theo chuan BCD dau.
Vi' du ban dung thong tin sau de "initialize" con timer IC:
gia^y : 45 second
Phut : 37 phu't
Gio : 8 gio.
Thi ban phai dung cai data sau day de dua vao : 0x45, 0x37, 0x08
sau khi dua vao, gia su*? 50 giay sau, ba.n doc cai thoi gio tu con IC, luc no' con IC se cho ban data sau:
Giay = 0x35
Phut = 0x38
Gio = 0x08
Neu ban muon hien thi. tren LCD cho du'ng thi ban phai doi ra nhu sau:
char second_digit1, second_digit2;
second_digit2 = (Giay / 0x10) + '0' = (0x35 / 0x10) + 0x30 = 0x33
second_digit1 = (Giay % 0x10) + '0' = (0x35 % 0x10) + 0x30 = 0x35
roi ban co' the display giong nhu display character:
lcd_display_char(second_digit2);
lcd_display_char(second_digit1);
Ban cu lam nhu vay, minh tin chac ban se da.p duoc yeu cau. Neu ban co' thac mac gi, thi cu hoi tiep nhe'.
VNBTECH
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