Texas Instruments TMS320C28x, Reference Manual

Page: 506 / 695

SUBCUL ACC,loc32
6-349
Example 4
; Calculate signed: Quot64 = Num364Den32, Rem32 = Num64%Den32
MOVL ACC,@Num64+2 ; Load ACC:P with 64-bit numerator
MOVL P,@Num64+0
TBIT @AH,#15 ; TC = sign of numerator
SBF $10,NTC ; Take absolute value of numerator
NEG64 ACC:P
$10:
MOVL @XAR3,P ; Temp save numerator low in XAR3
MOVL P,@ACC ; Load P register with numerator high
MOVL ACC,@Den32 ; Load ACC with contents of Den32
ABSTC ACC ; Take absolute value, TC = sign ^ TC
MOVL XT,@ACC ; Temp save denominator in XT register
MOVB ACC,#0 ; Zero ACC
RPT #31 ; Repeat operation 32 times
||SUBCUL ACC,@XT ; Conditional subtract with denominator
MOVL @XAR4,P ; Store high quotient in XAR4
MOVL P,@XAR3 ; Load P with low numerator
RPT #31 ; Repeat operation 32 times
||SUBCUL ACC,@XT ; Conditional subtract with denominator
MOVL @Rem32,ACC ; Store remainder in Rem32
MOVL ACC,@XAR4 ; Load ACC with high quotient from XAR4
SBF $20,NTC ; Take absolute value of quotient
NEG64 ACC:P
$20:
MOVL @0,P ; Store low quotient into Quot64
MOVL @2,ACC ; Store high quotient into Quot64