Expressions

Indexing

coefs[3]
coefs[3:0]
coefs[{5,3,1}]

Signals

Reference

V(out)
I(in,gnd)
V(in[1])

Operators

Arithmetic Operators

Reference

Symbol	Usage	Description
`+`	`a + b`	Sum `a` and `b`
`-`	`a - b`	Subtract `b` from `a`
`-`	`-a`	Negate `a`
`*`	`a * b`	Multiply `a` and `b`
`/`	`a / b`	Divide `a` by `b`
`%`	`a % b`	Modulus (remainder) of `a/b`
`**`	`a ** b`	`a` raised to the power of `b`

Bitwise Operators

Reference

Symbol	Usage	Description
`~`	`~a`	Invert each bit of `a`
`&`	`a&b`	Logical ‘and’ of each bit of `a` and `b`
`~&`	`a~&b`	Logical ‘nand’ of each bit of `a` and `b`
`\|`	`a\|b`	Logical ‘or’ of each bit of `a` and `b`
`~\|`	`a~\|b`	Logical ‘nor’ of each bit of `a` and `b`
`^`	`a^b`	Logical ‘xor’ of each bit of `a` and `b`
`~^`	`a~^b`	Logical ‘xnor’ of each bit of `a` and `b`
`^~`	`a^~b`	Same as `~^`

Reduction Operators

Reference

Symbol	Usage	Description
`&`	`&a`	Logical ‘and’ all bits in `a` to form 1 bit result
`~&`	`~&a`	Logical ‘nand’ all bits in `a` to form 1 bit result
`\|`	`\|a`	Logical ‘or’ all bits in `a` to form 1 bit result
`~\|`	`~\|a`	Logical ‘nor’ all bits in `a` to form 1 bit result
`^`	`^a`	Logical ‘xor’ all bits in `a` to form 1 bit result
`~^`	`~^a`	Logical ‘xnor’ all bits in `a` to form 1 bit result
`^~`	`^~a`	Same as `~^`

Logical Operators

Reference

Symbol	Usage	Description
`!`	`!a`	Is `a` false?
`&&`	`a&&b`	Are both `a` and `b` true?
`\|\|`	`a\|\|b`	Are either `a` or `b` true?

Equality Operators

Reference

Symbol	Usage	Description
`==`	`a==b`	Is `a` equal to `b`?
`!=`	`a!=b`	Is `a` not equal to `b`?

Identity Operators

Reference

Symbol	Usage	Description
`===`	`a===b`	Is `a` identical to `b`?
`!==`	`a!==b`	Is `a` not identical to `b`?

Relational Operators

Reference

Symbol	Usage	Description
`<`	`a<b`	Is `a` less than `b`?
`>`	`a>b`	Is `a` greater than `b`?
`<=`	`a<=b`	Is `a` less than or equal to `b`?
`>=`	`a>=b`	Is `a` greater than or equal to `b`?

Shift Operators

Reference

Symbol	Usage	Description
`<<`	`a<<b`	Shift `a` left `b` bits, vacated bits are filled with 0
`>>`	`a>>b`	Shift `a` right `b` bits, vacated bits are filled with 0
`<<<`	`a<<<b`	Shift `a` left `b` bits, vacated bits are filled with 0
`>>>`	`a>>>b`	Shift `a` right `b` bits, vacated bits are filled with 0 if `a` is unsigned and by the sign bit of `a` otherwise

Miscellaneous Operators

Reference

Symbol	Usage	Description
`? :`	`a ? b : c`	Evaluated to `b` if `a` is true and `c` otherwise
`{}`	`{a,b}`	Concatenates sized bit vectors `a` and `b`
`{{}}`	`{a{b}}`	Replicate `b`, `a` times

Size of Integer Results

Reference

Form	Operators	Size
i op j	`+`, `-`, `*`, `/`, `%`, `&`, `\|`, `^`, `^~`	max(L(i), L(j))
op i	`+`, `-`, `~`	L(i)
i op j	`==`, `!=`, `===`, `!==`, `&&`, `\|\|`, `>`, `>=`, `<`, `<=`	1
op i	`&`, `~&`, `\|`, `~\|`, `^`, `~^`	1
i op j	`>>`, `<<`	L(i)
i ? j : k		max(L(j), L(k)
{i, …, j}		L(i) + … + L(j)
{i {j, …, k}}		i `*` (L(j) + … + L(k))

Math Functions

Reference

Verilog-A and Verilog-AMS support the following functions.

Function	Description
`ln(x)`	Natural logarithm (base e)
`log(x)`	Common logarithm (base 10)
`exp(x)`	Exponential
`sqrt(x)`	Square root: √`x`
`min(x,y)`	Minimum
`max(x,y)`	Maximum
`abs(x)`	Absolute value
`floor(x)`	Floor (largest integer less than or equal to `x`)
`ceil(x)`	Ceiling (smallest integer greater than or equal to `x`)
`pow(x,y)`	Power: `x`^y (`y` must be integer if `x` < 0)
`sin(x)`	Sine (argument is in radians)
`cos(x)`	Cosine (argument is in radians)
`tan(x)`	Tangent (argument is in radians)
`asin(x)`	Arc sine (result is in radians)
`acos(x)`	Arc cosine (result is in radians)
`atan(x)`	Arc tangent (result is in radians)
`atan2(y,x)`	Angle from the origin to the point `x`, `y`
`hypot(x,y)`	Distance from the origin to the point `x`, `y`; `hypot(x,y)` = √(x² + y²)
`sinh(x)`	Hyperbolic sine (argument is in radians)
`cosh(x)`	Hyperbolic cosine (argument is in radians)
`tanh(x)`	Hyperbolic tangent (argument is in radians)
`asinh(x)`	Hyperbolic arc sine (result is in radians)
`acosh(x)`	Hyperbolic arc cosine (result is in radians)
`atanh(x)`	Hyperbolic arc tangent (result is in radians)
`$abstime`	The current time in seconds
`$realtime`	The current time in the current Verilog time units.
`$temperature`	The ambient temperature
`$vt`	The thermal voltage (V_T = kT/q) at the ambient temperature
`$vt(T)`	The thermal voltage (V_T = kT/q) at the given temperature

Verilog, SystemVerilog, and Verilog-AMS all support the following functions.

Function	Description
`$clog2(x)`	Ceiling of the base-2 logarithm
`$ln(x)`	Natural logarithm (base e)
`$log10(x)`	Common logarithm (base 10)
`$exp(x)`	Exponential
`$sqrt(x)`	Square root: √`x`
`$floor(x)`	Floor (largest integer less than or equal to `x`)
`$ceil(x)`	Ceiling (smallest integer greater than or equal to `x`)
`$pow(x,y)`	Power: `x`^y (`y` must be integer if `x` < 0)
`$sin(x)`	Sine (argument is in radians)
`$cos(x)`	Cosine (argument is in radians)
`$tan(x)`	Tangent (argument is in radians)
`$asin(x)`	Arc sine (result is in radians)
`$acos(x)`	Arc cosine (result is in radians)
`$atan(x)`	Arc tangent (result is in radians)
`$atan2(y,x)`	Angle from the origin to the point `x`, `y`
`$hypot(x,y)`	Distance from the origin to the point `x`, `y`;
`$hypot(x,y)`	√(x² + y²)
`$sinh(x)`	Hyperbolic sine (argument is in radians)
`$cosh(x)`	Hyperbolic cosine (argument is in radians)
`$tanh(x)`	Hyperbolic tangent (argument is in radians)
`$asinh(x)`	Hyperbolic arc sine (result is in radians)
`$acosh(x)`	Hyperbolic arc cosine (result is in radians)
`$atanh(x)`	Hyperbolic arc tangent (result is in radians)

Random Functions

Reference

Function	Description
`$random(seed)`	Uniformly distributed random 32-bit integer
`$dist_uniform(seed, lb, ub)`	Uniformly distributed random integer
`$rdist_uniform(seed, lb, ub)`	Uniformly distributed random real value
`$dist_normal(seed, mean, sd)`	Normally distributed random integer
`$rdist_normal(seed, mean, sd)`	Normally distributed random real value
`$dist_exponential(seed, mean)`	Exponentially distributed random integer
`$rdist_exponential(seed, mean)`	Exponentially distributed random real value
`$dist_poisson(seed, mean)`	Poisson distributed random integer
`$rdist_poisson(seed, mean)`	Poisson distributed random real value
`$dist_chi_square(seed, dof)`	Chi square distributed random integer
`$rdist_chi_square(seed, dof)`	Chi square distributed random real value
`$dist_t(seed, dof)`	Student T distributed random integer
`$rdist_t(seed, dof)`	Student T distributed random real value
`$dist_erlang(seed, k, mean)`	Erlang distributed random integer
`$rdist_erlang(seed, k, mean)`	Erlang distributed random real value

Analog Operators

Reference

Operator	Description
`ddt(operand, [abstol\|nature])`	Time derivative
`idt(operand, [ic], [assert], [abstol\|nature])`	Time integral
`idtmod(operand, [ic], [modulus], [offset], [abstol\|nature])`	Circular integrator
`transition(operand, delay, trise, [tfall])`	Transition
`slew(operand, [rising_sr], [falling_sr])`	Slew
`absdelay(operand, delay, [max_delay])`	Delay
`laplace_zp(operand, [zeta], [rho], [epsilon])`	Laplace, zero-pole form
`laplace_nd(operand, [n], [d], [epsilon])`	Laplace, numerator-denominator form
`laplace_zd(operand, [zeta], [d], [epsilon])`	Laplace, zero-denominator form
`laplace_np(operand, [n], [rho], [epsilon])`	Laplace, numerator-pole form
`zi_zp(operand, [zeta], [rho], T, tau, t0)`	Z transform, zero-pole form
`zi_nd(operand, [n], [d], T, tau, t0)`	Z transform, numerator-denominator form
`zi_zd(operand, [zeta], [d], T, tau, t0)`	Z transform, zero-denominator form
`zi_np(operand, [n], [rho], T, tau, t0)`	Z transform, numerator-pole form
`last_crossing(operand, [direction])`	Last crossing
`limexp(operand)`	Limited exponential

Small-Signal Stimulus Functions

Reference

Function	Description
`ac_stim([name], [mag], [phase]))`	AC stimulus
`white_noise(pwr, [name])`	White noise
`flicker_noise(pwr, [exp], [name])`	Flicker noise
`noise_table(pwr, [name])`	Noise table

File Operations

Reference

Function	Description
`fopen(filename, mode))`	File open
`fclose(file)`	File close