Chapter 2 : Data types

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Chapter 2 Data types
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Extension Data Type Overview
Name Description
sc_bit single bit with two values, 0 and 1
sc_bvltngt Arbitrary width bit vector
sc_logic Signle bit with four value, 0, 1, X and Z
sc_lvltngt Arbitrary width logic vector
sc_intltngt Signed integer type , up to 64 bits
sc_uintltngt Unsigned integer type, up to 64 bits
sc_bigintltngt Arbitrary width signed integer type
sc_bituintltngt Arbitrary width signed integer type
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sc_bit
Operator Function Usage
Bitwise AND expr1 expr2
Bitwise OR expr1 expr2
Bitwise XOR expr1 expr2
Bitwise NOT expr1
Assignment value_holder expr
Compound AND value_holder expr
Compound OR value_holder expr
Compound XOR value_holder expr
Equality expr1 expr2
Inequality expr1 ! expr2
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sc_bvltngt
Operator Function Usage
Bit selection varindex
(,) Concatenation (expr1, expr2, expr3)
Method Function Usage
range(0 Range selection var.range(idx1, idx2)
and_reduce() Reduction AND var.and_reduce()
or_reduce Reduction OR var.or_reduce()
xor_reduce Reduction XOR var.xor_reduce()
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sc_logic and sc_lvltngt

• Four value
• 0, SC_LOGIC_0
• 1, SC_LOGIC_1
• X, SC_LOGIC_X
• Z, SC_LOGIC_Z
• Operation
• The same as sc_bit

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Integer Type

• Data width lt 64 bits
• sc_int
• sc_uint
• Data width gt 64 bits
• sc_bitint
• sc_biguint
• Operation
• The same as C native definition
• , (,), range()

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User Defined Data

• Four operator are required
• Operator (assignment)
• Operator (equality)
• Operator ltlt (stream output)
• sc_trace()
• Example
• struct blah
• int a, int b
• blah operator (const blah arg)
• a arg.a, b arg.b
• bool operatro (const blah arg)
• return a arg.a b arg.b ? true
  false
• ostream operatorltlt (ostream os, const
  blah arg)
• os ltlt a ltlt arg.a ltlt b ltlt b
• void sc_trace (sc_trace_file tf, const blah
  arg, const sc_string name)
• sc_trace(tf, arg.a, name.a
• sc_trace(tf, arg.b, name.b

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Example

• sc_logic x // object declaration
• x 1 // assign a 1 value
• x Z // assign a Z value
• sc_bvlt16gt val
• val "1111111111111111"
• sc_uintlt4gt myrange
• sc_uintlt32gt myint
• myrange myint.range(7,4)
• sc_uintlt4gt inta
• sc_uintlt4gt intb
• sc_uintlt8gt intc
• intc (inta, intb)

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Recommended Data Types

• Primitive type is better
• For one bit, use bool
• Replace sc_int and sc_uint by int and unsigned
  int if acceptable
• Use sc_logic and sc_lv types when four types are
  really needed