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(2) Numeric representation in BIN
(a) Bit configuration of BIN used in the CPU module
Each register (such as the data register, link register) in the CPU module consists of 16 bits.
(b) Numeric data available in the CPU module
Each register in the CPU module can store numeric values in the range of -32768 to 32767.
Figure 2.37 shows the numeric representations for registers.
A numeric value of 2
n
is assigned for each bit of registers.
Note that an unsigned binary number (0 to 65535) cannot be used in the most significant bit position since the
most significant bit is a sign bit.
• The most significant bit is "0"...Positive
• The most significant bit is "1"...Negative
Figure 2.37 Numeric representations for registers in the CPU module
b15
8192
Bit name
Decimal value
Most significant bit (sign bit)
A value will be negative value when the most significant bit is "1".
16384
4096 2048 1024 512 256 128 64 32 16 8 4 2 1
-32768
2
15
2
14
2
13
2
12
2
11
2
10
2
9
2
8
2
7
2
6
2
5
2
4
2
3
2
2
2
1
2
0
b14 b13 b12 b11 b10 b9 b8 b7 b6 b5 b4 b3 b2 b1 b0
