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# ST1 (vector, single structure)

Store single 1-element structure from one lane of one register.

### Syntax

``` ST1 { Vt.B }[index], [Xn|SP] ; 8-bit ```

``` ST1 { Vt.H }[index], [Xn|SP] ; 16-bit ```

``` ST1 { Vt.S }[index], [Xn|SP] ; 32-bit ```

``` ST1 { Vt.D }[index], [Xn|SP] ; 64-bit ```

``` ST1 { Vt.B }[index], [Xn|SP], #1 ; 8-bit, immediate offset, Post-index ```

``` ST1 { Vt.B }[index], [Xn|SP], Xm ; 8-bit, register offset, Post-index ```

``` ST1 { Vt.H }[index], [Xn|SP], #2 ; 16-bit, immediate offset, Post-index ```

``` ST1 { Vt.H }[index], [Xn|SP], Xm ; 16-bit, register offset, Post-index ```

``` ST1 { Vt.S }[index], [Xn|SP], #4 ; 32-bit, immediate offset, Post-index ```

``` ST1 { Vt.S }[index], [Xn|SP], Xm ; 32-bit, register offset, Post-index ```

``` ST1 { Vt.D }[index], [Xn|SP], #8 ; 64-bit, immediate offset, Post-index ```

``` ST1 { Vt.D }[index], [Xn|SP], Xm ; 64-bit, register offset, Post-index ```

Where:

`Vt`

Is the name of the first or only SIMD and FP register to be transferred.

`index`

The value depends on the instruction variant:

8-bit

For the 8-bit variant: is the element index, in the range 0 to 15.

16-bit

For the 16-bit variant: is the element index, in the range 0 to 7.

32-bit

The element index, in the range 0 to 3.

64-bit

The element index, and can be either 0 or 1.

`Xn|SP`

Is the 64-bit name of the general-purpose base register or stack pointer.

`Xm`

Is the 64-bit name of the general-purpose post-index register, excluding XZR.