Texas Instruments C2000

Control Law Computation
A
1
A
2
B
0
B
1
B
2
)2()1()2()1()()(
21210
−
+
−
+
−
+
−
+
=
nUAnUAnEBnEBnEBnU
; e(n)=Vref-Vout
MOVU ACC,@Vref
SUBU ACC,*XAR2++
LSL ACC,#8 ; ACC=e(n) (Q24)
MOVL @VCNTL_DBUFF+4,ACC
ZAPA
; Voltage control law
MOVL XT,@VCNTL_DBUFF+8 ; XT=e(n-2)
QMPYAL P,XT,*XAR7++ ; b2*e(n-2)
MOVDL XT,@VCNTL_DBUFF+6 ; XT=e(n-1), e(n-2)=e(n-1)
QMPYAL P,XT,*XAR7++ ; ACC=b2*e(n-2), P=b1*e(n-1)
MOVDL XT,@VCNTL_DBUFF+4 ; XT=e(n), e(n-1)=e(n)
QMPYAL P,XT,*XAR7++ ; ACC+=b1*e(n-1), P=b0*e(n)
MOVL XT,@VCNTL_DBUFF+2 ; XT=u(n-2)
QMPYAL P,XT,*XAR7++ ; P=a2*u(n-2)
MOVDL XT,@VCNTL_DBUFF ; XT=u(n-1), u(n-2)=u(n-1)
QMPYAL P,XT,*XAR7++ ; ACC=a2*u(n-2)
ADDL ACC,P ; ACC=a2*u(n-2)+a1*u(n-1)
LSL ACC,#(23-VCNTL_QF+8) ; (Q23)
ADDL ACC,ACC ; (Q24)
MOVL @VCNTL_DBUFF,ACC ; ACC=u(n)
; Saturate the result [min,max]
MINL ACC,*XAR7++
MAXL ACC,*XAR7++
; Duty Cycle Modulation
MOVL XT,ACC
QMPYL P,XT,*XAR7++ ;(Q0)
MOV *XAR3++,P
XAR7
min
max
duty
U(n)
U(n-1)
U(n-2)
E(n)
E(n-1)
E(n-2)
DBUFF