---
title: SetClockDomain
framework: VideoDriverKit
role: symbol
role_heading: Instance Method
platforms: [driverkit 27.0+]
path: videodriverkit/iouservideoclockdevice/setclockdomain
---

# SetClockDomain

Sets the clock domain value of the clock device.

## Declaration

```occ
kern_return_t SetClockDomain(uint32_t in_clock_domain);
```

## Parameters

- `in_clock_domain`: The uint32_t clock domain value to set.

## Return Value

Return Value A kern_return_t value indicating success or failure.

## Discussion

Discussion A uint32_t whose value indicates the clock domain to which the IOUserVideoClockDevice belongs. IOUserVideoClockDevices that have the same value for this property can synchronize in hardware. However, a value of 0 indicates that the clock domain for the device is unspecified; treat it as separate from every other device’s clock domain, even if they have the value of 0 as their clock domain as well. Drivers can change the clock domain of the clock device dynamically. If successful, the clock device sends a notification to the host to update the object state.

## See Also

### Working with the clock domain

- [GetClockDomain](videodriverkit/iouservideoclockdevice/getclockdomain.md)