tham chi hang trieu c6ng logic vai each ket noi co kha nang lap trinh duge va
thuong duoe su dung cho cac qua trinh phat trien phan cung phiic tap.
Trong bai bao nay, chiing tci ehgn d6i tugng la cac chip CPLD co muc do phiic
tap a miic trung binh trong 3 loai chip kk tren. Tuy vay cac chip CPLD da cho phep
Bao cao tai Hoi nghi Vat ly Toan quoc Ian thu VI, Ha Noi 23-25 /ll/2005
Cac he thong do lucmg vat ly gan day dku bao g6m hai phdn chinh la[2]: cam biln
va khoi xu ly tin hieu tir cam bien voi muc do phuc tap tuong xung voi cac chip
CPLD. Vi vfy, chung toi lira chon chip CPLD dk xay dung mot he thdng do luona vat ly bao gom: do nhiet do o nam vi tri, do do km tir mot vi tri va hi^n thi trin 3 man hien thi LED bay thanh khac nhau: mot cho nhiet do a mot vi tri, mot cho do
am va mot cho nhiet do trung binh tir 4 vi tri con lai.
PHAN THirc NGHIEM
• •
Chip CPLD duoc lira chon de tiln hanh thuc nghiem la loai XC95361'] ciia cong ty Xilinx voi 44 chan, tren chip tich hgp 36 macrocell voi 800 cdng sir dung duoc. ^ Theo thiet ke truygn thdng thi he thdng do tren day se bao gdm 5 cam bi^n nhiet. mot cam bien do dm, cac mach chuin tin hieu tir cam biln, cac bd bi^n ddi tuong tu-sd de chuyen tin hieu vao mot vi xir ly, cudi ciing la cac khdi giai ma va dieu khien de dua ra 3 bd hi6n thj LED 7 thanh. So dd khdi cua he thdng cd tha hinh dung la rdt phuc tap. De don gian cho viec tich hop tren chip, he thdng duoc chia ra thanh nhirng mddun va riit gon thanh so ddi khdi nhu hinh 1.
CBND 1 CBND 2 CBND 2 CBND 3 CBND 4 _ ^ "r CBND 5 1 -^ i PSoC 1 CBDA • ^ ~ ~ XC9536 • ^ - , \ . \ . 7 ^ LEDl NhdoTB ^ s LED 2 Nhdo 5 t ' . LED 3 Dp am
Hinh 1: So* do khoi cua he thong sir dung cac chip lap trinh dirac.
Cam bian nhiet do duge su dung la loai NTC833 (do -400C din lOO^C), con
cam bien do am la loai HM1520 (cua Honeywell), nghia la tin hieu o loi ra ciia cac
f •> -i r ,
cam bien deu la tin hieu dien ap nen phan xii ly tin hieu sau cam bien co ca khoi
' r t f
khuech dai va bien doi tuong tu so. Do vay, chip PSoC CY8C27443 da duge lua ehgn. Cong cu PSoC Designer ciia Cypress cho phep tu cac tai nguyen co san thiet lap cac bg khuech dai co he so khuech dai dat duge va bg bien doi AD tuong tu-so voi do phan giai dat duge. Do viec hien thi nhiet do va do am chi can den 3 con so (digit) nen do phan giai trong truong hgp nay duge dat la 10 bit. Chip PSoC duge lap trinh bang Assembly de thuc hien vai tro cua mot vi dieu khien, cu the la Ian lugt dgc dii lieu tir cac cam bien roi xii ly va chuyen sang chip XC9536 de dua ra hien thi
De dua ra so do don gian nay, ro rang la mot so modun da duge tich hgp vao trong chip CPLD. Cu tha la: