Builtin Type

4-state data type which has variable width

logic is 4-state (0, 1, x, z) data type. The variable width can be specified by <> after logic. Multi-dimentional can be specified by <X, Y, Z,,,>.

module ModuleA {
    let _a: logic         = 1;
    let _b: logic<10>     = 1;
    let _c: logic<10, 10> = 1;
}

2-state data type which has variable width

bit is 2-state (0, 1) data type. The variable width can be specified by <> after bit. Multi-dimentional can be specified by <X, Y, Z,,,>.

module ModuleA {
    let _a: bit         = 1;
    let _b: bit<10>     = 1;
    let _c: bit<10, 10> = 1;
}

Type modifier

The following type modifiers can be added to logic and bit type.

• signed: the MSB is treated as sign-bit
• tri: tri-state type

module ModuleA {
    let _a: signed logic<10> = 1;
    let _b: tri logic   <10> = 1;
    let _c: signed bit  <10> = 1;
    let _d: tri bit     <10> = 1;
}

Integer type

There are some integer types:

• u8 : 8bit unsigned integer
• u16: 16bit unsigned integer
• u32: 32bit unsigned integer
• u64: 64bit unsigned integer
• i8 : 8bit signed integer
• i16: 16bit signed integer
• i32: 32bit signed integer
• i64: 64bit signed integer

module ModuleA {
    let _a: u8  = 1;
    let _b: u16 = 1;
    let _c: u32 = 1;
    let _d: u64 = 1;
    let _e: i8  = 1;
    let _f: i16 = 1;
    let _g: i32 = 1;
    let _h: i64 = 1;
}

Floating point type

There are some floating point types:

• f32: 32bit floating point
• f64: 64bit floating point

Both of them are represented as described by IEEE Std 754.

module ModuleA {
    let _a: f32 = 1.0;
    let _b: f64 = 1.0;
}

String type

string is string type.

module ModuleA {
    let _a: string = "";
}

Type type

type is a type which represents type kind. Variable of type can be defined as param or const only.

module ModuleA {
    const a: type = logic;
    const b: type = logic<10>;
    const c: type = u32;
}

Boolean type

bool is a type alias of logic<1> to express boolean. true and false literal which express 1'b1 and 1'b0 can be used.

module ModuleA {
    const a: bool = true;
    const b: bool = false;
}