Motorola DSP96002 User Manual page 690

; ***
; ***
; ***
; ***
; ***
; ***
; ***
; *** Routine Inputs:
; *** d6 - IEEE double extended precision operand 1
; *** d7 - IEEE double extended precision operand 2
; ***
; *** Routine Outputs:
; *** d5 - IEEE double extended precision result
; ***
; *** Registers Used:
; *** d0.l - general purpose usage
; *** d0.m - unbiased operand 2 exponent
; ***
; *** d0.h - MSB contains the XOR of the sign bits
; *** d1.l - general purpose usage
; *** d1.m - unbiased operand 1 exponent
; ***
; *** d1.h - LSB contains the sticky bit
; *** d2.m,l - partial product and intermediate calculations
; *** d3.m,l - partial product and intermediate calculations
; *** d4.m,l - partial product and intermediate calculations
; *** d5.m,l - partial product and intermediate calculations
; ***
; *** NOTES: Currently ignores the FR, P, RP bits.
; ***
; ***
; ***
; ***
section ieeemult
SR_MASK equ
EXP_MSK equ
EBIAS equ
EMAX equ
EMIN equ
EDEN equ
MAX equ
SMSK equ
INUM equ
sdptest
; ****** Define Program Macros ******
depftst macro
; This macro performs the "ftst" function on DEP floating pt vars.
; It sets the NAN,I,N,Z bits in the CCR register appropriately.
;
; op = register name of the form "Dn" containing the floating pt var
; in all 96 bits of the register (not destroyed)
MOTOROLA
f = fraction bits, initially bits in mantissas
l = least significant fraction bit, initially in mantissas
g = guard bit
r = round bit
s - sticky bit
- unbiased result exponent
- loop index for denormalizing upon underflow.
Assumes that operands are NOT UNnormalized numbers
Code size greatly decreased if "depftst" macro
becomes a routine
$ffff80c0 ; Status Register Mask, resets cond. codes
$7ff ; Mask for exponent field, 16-bits
$3ff ; Exponent bias for IEEE double precision
$3ff ; Max exp for normalized double precision val
$fffffc02 ; Min exp for normalized double precision val
$fffffc01 ; Exp for denormalized double precision val
$7ff ; Max exp (biased), indicating infs & NaNs
$1ff ; Mask for sticky bit calculation
$800 ; Increment for LSB
; double precision multiplication subroutine
op,tmp1,tmp2
DSP96002 USER'S MANUAL
(destroyed)
(destroyed)
B-171