Smart.BitField displays a hardware register as its individual bits, with the word value and the bits kept in sync.

A register has a fixed width, named and reserved bits, an MSB-first or LSB-first display order, and a word value that always matches the bits. The component keeps the word and the bits in sync, so the application does not have to maintain a boolean array and a numeric value separately.

A named status register

Click a bit to toggle it, or press Tab to focus the register and use the arrow keys. Reserved bits are drawn dashed and cannot be changed.

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Word lengths

Values are held as BigInt, so 64-bit registers are represented exactly. A JavaScript number loses integer precision above 2⁵³ and cannot hold a uint64 value.

The int16 row shows the same bit pattern as a signed decimal value.

Bit order

Hardware documentation is written MSB-first, with bit 15 on the left for a 16-bit register, so this is the default. The bitOrder property changes the display order only; bits are always numbered from the least significant bit.