W90221X Winbond Electronics Corp America, W90221X Datasheet - Page 207

• Manufacturer Part Number: W90221X
• Description: Pa-risc Embedded Controller
• Manufacturer: Winbond Electronics Corp America

Halfword Multiply And Accumulate Unsign
Format:
Purpose: To multiply two unsigned 16-bit halfword of GR[r1] and GR[r2] register,
then accumulate {HI, LO} register with the multiplied result.
Description: The corresponding 16-bit halfwords of GR[r1] and GR[r2] are
interpretted as unsigned 16-bit operands, and are arithmetically multiplied and add
the product to the present contents of the {HI, LO} register, the 64-bit result is placed
in {HI, LO} register and GR[t], the bit in AIR[25] which indicates operating in integer
or fraction mode determines the high-order halfword or low-order halfword of GR[r1],
GR[r2] will be as the two operands .
truncated the lower 16 bits when the least 16th bit is zero. IF the the least 16th bit is
one, add one the high-order 16 bits and truncate the low-order 16 bits.
Operation:
Integer mode operation (AIR[25] = 0) :
switch (cmplt) {
zero_ext(GR[r2]{16:31})
zero_ext(GR[r2]{16:31})
zero_ext(GR[r2]{16:31}){32:63};
zero_ext(GR[r2]{16:31});
}
Fraction mode operation (AIR[25] = 1) :
switch(cmplt) {
zero_ext(GR[r2]{0:15}),
W90221X version 0.6
The completer "r" indicates operating in rounding mode, the multiply result can be
05
0:5
case r : (r=1, rounding mode){
default : (r=0, unrounding mode){
6
case r : (r=1, rounding mode){
r2
6:10
GR[t]{0:31}
GR[t]{0:31}
{HI, LO}
5
break;
{HI, LO}
GR[t]{0:31}
break;
}
}
HMACU, cmplt
r1
11:15
5
~
16:18
3
1) + 16h8000){32:63};
+16h8000)){0:63};
({HI,
+ 16h8000)){32:63};
r
{HI,
({HI,
19
1
({HI, LO} + (zero_ext(GR[r1]{16:31}) *
1
LO}
r1,r2,t
{HI, LO} + zero_ext(GR[r1]{16:31}) *
LO}
LO}
20
1
02
+
+
+
lshift(zero_ext(GR[r1]{0:15})
21:25
~
((zero_ext(GR[r1]{16:31})
5
zero_ext(GR[r1]{16:31})
t
26
1
27:31
5
HMACU
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