Multiplication Section
3-5
Central Processing Unit
3.2
Multiplication Section
The ’C2xx uses a 16-bit
×
16-bit hardware multiplier that can produce a signed
or unsigned 32-bit product in a single machine cycle. As shown in Figure 3–5,
the multiplication section consists of:
-
The 16-bit temporary register (TREG), which holds one of the multipli-
cands
-
The multiplier, which multiplies the TREG value by a second value from
data memory or program memory
-
The 32-bit product register (PREG), which receives the result of the multi-
plication
-
The product shifter, which scales the PREG value before passing it to the
CALU.
Figure 3–5. Block Diagram of the Multiplication Section
32
MUX
PREG
Multiplier
16
×
16
16
TREG
Product shifter (32 bits)
Multiplication
section
From data memory
16
From data
memory
16
From program memory
16
To CALU
32
From data memory
16
16
To data memory
To high word
of PREG
3.2.1
Multiplier
The 16-bit
×
16-bit hardware multiplier can produce a signed or unsigned
32-bit product in a single machine cycle. The two numbers being multiplied are
treated as 2s-complement numbers, except during unsigned multiplication
(MPYU instruction). Descriptions of the inputs and output of the multiplier fol-
low.
