ST20C2 View Datasheet(PDF) - STMicroelectronics

Part Name

Description

Manufacturer

ST20C2

Instruction Set Reference Manual

STMicroelectronics 

Symbol

Meaning

Integer arithmetic with overflow checking

+checked

−checked

×checked

Add, subtract, and multiply of signed integers. If the computation overflows an

IntegerOverflow is signalled and the result of the operation is truncated to the

word length.

Unchecked (modulo) integer arithmetic

+

Integer add, subtract, multiply, divide and remainder. If the computation over-

−

flo ws the result of the operation is truncated to the word length. If a divide or

×

remainder by zero occurs the result of the operation is undefined. No errors are

/

signalled. The operator ‘−’ is also used as a monadic operator. The sign of the

rem

remainder is the same as the sign of the dividend.

Signed comparison operators

<

Comparisons of signed integer and floating point v alues: ‘less than’, ‘greater

>

than’, ‘less than or equal’, ‘greater than or equal’, ‘equal’ and ‘not equal’.

≤

≥

=

≠

Unsigned comparison operators

<unsigned

>unsigned

≥unsigned

after

Comparisons of unsigned integer values: ‘less than’, ‘greater than’, ‘greater than

or equal’, and ‘after’ (for comparison of times).

Logical bitwise operations

∼ (or BITNOT)

∧ (or BITAND)

∨ (or BITOR)

⊗ (or BITXOR)

>>

<<

‘Not’ (1’s complement), ‘and’, ‘or’, ‘exclusive or’, and logical left and right shift

operations on bits in words.

Boolean operators

not

Boolean combination in conditionals.

and

or

Table 1.7 Operators used in the instruction descriptions

• if condition

statement

else if condition

statement

else

statement

These conditions can be nested. Braces, {}, are used to group statements which are

dependent on a condition. For example, the cj (conditional jump) instruction contains

the following lines:

if (Areg = 0)

IptrReg′ ← next instruction + n

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