> ## Documentation Index
> Fetch the complete documentation index at: https://voltaire.tevm.sh/llms.txt
> Use this file to discover all available pages before exploring further.

# Memory

> Auto-generated API documentation

[**@tevm/voltaire**](../../index.mdx)

***

[@tevm/voltaire](../../index.mdx) / [evm](../index.mdx) / Memory

# Memory

## Functions

### mcopy()

> **mcopy**(`frame`): [`EvmError`](../index.mdx#evmerror) | `null`

Defined in: [src/evm/memory/0x5e\_MCOPY.js:41](https://github.com/evmts/voltaire/blob/bd6ec34405c15ad8cd51d11579d495dc53813482/src/evm/memory/0x5e_MCOPY.js#L41)

MCOPY opcode (0x5e) - Copy memory (EIP-5656, Cancun+)

Pops dest, src, len from stack. Copies len bytes from src to dest.
Handles overlapping regions correctly using temporary buffer.

Gas cost: GasFastestStep (3) + memory expansion cost + copy cost (3 gas per word)

Note: This opcode was introduced in the Cancun hardfork (EIP-5656).
Implementation assumes hardfork check is done externally.

#### Parameters

##### frame

[`BrandedFrame`](../index.mdx#brandedframe)

Frame instance

#### Returns

[`EvmError`](../index.mdx#evmerror) | `null`

Error if any

***

### mload()

> **mload**(`frame`): [`EvmError`](../index.mdx#evmerror) | `null`

Defined in: [src/evm/memory/0x51\_MLOAD.js:18](https://github.com/evmts/voltaire/blob/bd6ec34405c15ad8cd51d11579d495dc53813482/src/evm/memory/0x51_MLOAD.js#L18)

MLOAD opcode (0x51) - Load word from memory

Pops offset from stack, reads 32 bytes from memory starting at offset,
and pushes the result as a 256-bit value onto the stack.

Gas cost: GasFastestStep (3) + memory expansion cost

#### Parameters

##### frame

[`BrandedFrame`](../index.mdx#brandedframe)

Frame instance

#### Returns

[`EvmError`](../index.mdx#evmerror) | `null`

Error if any

***

### mstore()

> **mstore**(`frame`): [`EvmError`](../index.mdx#evmerror) | `null`

Defined in: [src/evm/memory/0x52\_MSTORE.js:17](https://github.com/evmts/voltaire/blob/bd6ec34405c15ad8cd51d11579d495dc53813482/src/evm/memory/0x52_MSTORE.js#L17)

MSTORE opcode (0x52) - Save word to memory

Pops offset and value from stack, writes 32 bytes to memory starting at offset.
Value is stored in big-endian format.

Gas cost: GasFastestStep (3) + memory expansion cost

#### Parameters

##### frame

[`BrandedFrame`](../index.mdx#brandedframe)

Frame instance

#### Returns

[`EvmError`](../index.mdx#evmerror) | `null`

Error if any

***

### mstore8()

> **mstore8**(`frame`): [`EvmError`](../index.mdx#evmerror) | `null`

Defined in: [src/evm/memory/0x53\_MSTORE8.js:17](https://github.com/evmts/voltaire/blob/bd6ec34405c15ad8cd51d11579d495dc53813482/src/evm/memory/0x53_MSTORE8.js#L17)

MSTORE8 opcode (0x53) - Save byte to memory

Pops offset and value from stack, writes the least significant byte
of value to memory at offset.

Gas cost: GasFastestStep (3) + memory expansion cost

#### Parameters

##### frame

[`BrandedFrame`](../index.mdx#brandedframe)

Frame instance

#### Returns

[`EvmError`](../index.mdx#evmerror) | `null`

Error if any