# MC14560BCP Freescale Semiconductor, Inc, MC14560BCP Datasheet - Page 10

#### MC14560BCP

Manufacturer Part Number

MC14560BCP

Description

Manufacturer

Freescale Semiconductor, Inc

Datasheet

1.MC14560BCP.pdf
(13 pages)

Arithmatic Expression

Inputs

(N = Number of Digits,

(N = Number of Digits,

A S

A S

B S

B S

C out

C out

A, B, R are Positive

A, B, R are Positive

A, B, R are Positive

“1” = Neg

“1” = Neg

“1” = Neg

“1” = Neg

“1” = Carry

“1” = Carry

0

0

0

R = A + 8

0

0

1

0

1

0

R = A – B

= A + (10 N – 1 – B)

= A – B + 10 N – 1

0

1

1

1

0

0

R = B – A

= B + (10 N – 1 – A)

= B – A + 10 N – 1

1

0

1

1

1

0

R = – A – B

= (10 N – 1 – A) +

= – (A + B) + 2 x

1

1

1

* Output of Adders

Figure 9. Truth Table Generation for EAC, Sign, and Overflow Logic

MC14560B

10

for R* (Result)

10 N = Modulus

10 N = Modulus

End Around

Carry (EAC)

Carry (EAC)

Magnitudes)

Magnitudes)

Magnitudes)

“1” = EAC

“1” = EAC

No EAC (“0”)

because R is correct

result.

No EAC (“0”)

because 9’s

complement

expression for R is

correct result.

EAC = “1” because

expression for R is in

error by 1.

No EAC (“0”)

because 9’s

complement

expression for R is

correct result.

EAC = “1” because

expression for R is in

error by 1.

EAC = “1” because

9’s complement

expression for R is in

(10 N – 1 – B)

error by 1.

10 N – 2

10 N – 2

Outputs

Sign of R

Sign of R

Overflow

Overflow

“1” = Negative

“1” = Negative

“1” = Overflow

“1” = Overflow

Since A and B are

When C out = “0”, there

is no carry (R < 10 N )

positive signed, R is

positive signed (“0”).

and thus no overflow

(“0”).

When C out = “1”, there

10 N )

is a carry (R

and thus overflow

(“1”).

v

A

B when C out =

“0”; thus sign of R

must be negative

(“1”).

A > B when C out =

“1”; thus sign of R

must be positive

There is never an

There is never an

(“0”).

overflow when

overflow when

overflow when

v

numbers of opposite

numbers of opposite

B

A when C out =

sign are added.

sign are added.

“0”; thus sign of R

must be negative

(“1”).

B > A when C out =

“1”; thus sign of R

must be positive

(“0”).

Since A and B are

When C out = “0”, there

is no Carry (R < 0 N )

negative signed. R is

and (A + B) > 10 N – 1

negative signed (“1”).

indicating overflow

(“1”).

When C out = “1”, there

10 N )

is a carry (R

v

10 N – 1

and (A + B)

indicating no overflow

(“0”).

MOTOROLA CMOS LOGIC DATA