HCS12 Assembly Programming - The HCS12/9S12: An Introduction to Software and Hardware Interfacing - page 75

The result is shown in Figure 2.12b.

Original value New value

[$1000] = 11101101
C = 0

[$1000] = 11110110
C = 1

Figure 2.12b ■ Result of the asr $1000 instruction

▲

Example 2.20
▼ What are the new values of the memory location at $1000 and the C flag after executing the
instruction lsr $1000 assuming that the memory location $1000 originally contains $E7 and the
C flag is 1?
Solution: The operation of this instruction is illustrated in Figure 2.13a.

1 11 0 0 1 1 1

Memory location
$1000

C flag

0 0 1 1 1 0 0 1 1 1

Figure 2.13a ■ Operation of the lsr $1000 instruction

The result is shown in Figure 2.13b.

Original value New value

[$1000] = 11100111
C = 1

[$1000] = 01110011
C = 1

Figure 2.13b ■ Execution result of lsr $1000

▲

Example 2.21
▼

What are the new values of accumulator B and the C flag after executing the rolb instruc-
tion assuming that the original value of B is $BD and the C flag is 1?
Solution: The operation of this instruction is illustrated in Figure 2.14a.