7 multiplier read register 1 (mc1r), 8 multiplier read register 0 (mc0r), 6 hardware multiplier examples – Maxim Integrated MAX31782 User Manual
Page 123: 14 .6 hardware multiplier examples -8, 6hardwaremultiplierexamples, 7multiplierreadregister1(mc1r), 8multiplierreadregister0(mc0r)
MaximIntegrated 14-8
MAX31782 User’s Guide
Revision 0; 8/11
14.5.7MultiplierReadRegister1(MC1R)
MultiplierReadRegister1:The MC1R register represents bytes 3 and 2 from the result of the last operation when
MCW = 1 or the last operation was a multiply or multiply-negate . When MCW = 0 and the last operation was a multiply-
accumulate/subtract, the contents of this register may or may not agree with the contents of MC1 due to the combinato-
rial nature of the adder . The contents of this register can change if MCNT, MA, MB, or MC[2:0] is changed .
14.5.8MultiplierReadRegister0(MC0R)
MultiplierReadRegister0:The MC1R register represents bytes 1 and 0 from the result of the last operation when
MCW = 1 or the last operation was a multiply or multiply-negate . When MCW = 0 and the last operation was a multiply-
accumulate/subtract, the contents of this register may or may not agree with the contents of MC0 due to the combinato-
rial nature of the adder . The contents of this register can change if MCNT, MA, MB, or MC[2:0] is changed .
14.6HardwareMultiplierExamples
The following are code examples of multiplier operations .
;Unsigned Multiply 16-bit x 16-bit
move MCNT, #21h
; CLD=1, SUS=1 (unsigned)
move MA, #0FFFh
; MC2:0=0000_0000_0000h
move MB, #1001h
; MC1R:MC0R= 00FF_FFFFh
; MC2:0=0000_00FF_FFFFh
;Signed Multiply 16-bit x 16-bit
move MCNT, #20h
; CLD=1, SUS=0 (signed)
move MA, #F001h
; MC2:0=0000_0000_0000h
move MB, #1001h
; MC1R:MC0R= FF00_0001h
; MC2:0=FFFF_FF00_0001h
;Unsigned Multiply-Accumulate 16-bit x 16-bit
; MC2:0=0000_0100_0001h
move MCNT, #03h
; MMAC=1, SUS=1 (unsigned)
move MA, #0FFFh
;
move MB, #1001h
;
; MC1R:MC0R=02FF_FFFFh
; MC2:0=0000_0200_0000h
Bit
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
Name
MC1R .15 MC1R .14 MC1R .13 MC1R .12 MC1R .11 MC1R .10 MC1R .9
MC1R .8
MC1R .7
MC1R .6
MC1R .5
MC1R .4
MC1R .3
MC1R .2
MC1R .1
MC1R .0
Reset
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Access
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
Bit
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
Name
MC0R .15 MC0R .14 MC0R .13 MC0R .12 MC0R .11 MC0R .10 MC0R .9
MC0R .8
MC0R .7
MC0R .6
MC0R .5
MC0R .4
MC0R .3
MC0R .2
MC0R .1
MC0R .0
Reset
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Access
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw