Calculator User Manual

Central Arithmetic Logic Section
3-8
3.3 Central Arithmetic Logic Section
Figure 3–6 shows the main components of the central arithmetic logic section,
which are:
The central arithmetic logic unit (CALU), which implements a wide range
of arithmetic and logic functions.
The 32-bit accumulator (ACC), which receives the output of the CALU and
is capable of performing bit shifts on its contents with the help of the carry
bit (C). Figure 3–6 shows the accumulator’s high word (ACCH) and low
word (ACCL).
The output shifter, which can shift a copy of either the high word or low
word of the accumulator before sending it to data memory for storage.
Figure 3–6. Block Diagram of the Central Arithmetic Logic Section
ACCH
32
32
Output shifter (32 bits)
32
C
ACCL
CALU
MUX
Central arithmetic logic
section
32
From product shifter
From input shifter
3232
To data memory
16