Toshiba H1 Series Data Book page 633

3.26.2 Description of Operation
(1) Calculation mode
The MAC has the following three types of calculation mode. The calculation mode to be used
is specified in MACCR<MOPMD1:0>. MACCR<MSMD> is used to select unsigned or signed
mode. The operation of each calculation mode is explained below.
(a) 64 + 32 × 32 mode
In this mode, the contents of the MACMA register and the MACMB register are
multiplied and the result is added to the contents of the MACOR register. Then, the result
is stored back in the MACOR register.
63
MACOR
(b) 64 − 32 × 32 mode
In this mode, the contents of the MACMA register and the MACMB register are
multiplied and the result is subtracted from the contents of the MACOR register. Then, the
result is stored back in the MACOR register.
63
MACOR
(c) 32 × 32 − 64 mode
In this mode, the contents of the MACMA register and the MACMB register are
multiplied and the contents of the MACOR register are subtracted from the result. Then,
the result is stored back in the MACOR register.
31
31 0
×
MACMA
31
0 31 0
+ ×
MACMA
31
0 31 0
− ×
MACMA
0
63
−
MACMB
MACOR
92CZ26A-630
63
MACMB
MACOR
63
MACMB
MACOR
0 63
TMP92CZ26A
0
0
0
MACOR