<!--
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  "availability" : [
    "DriverKit: 19.0 -"
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  "documentType" : "symbol",
  "framework" : "USBDriverKit",
  "identifier" : "/documentation/USBDriverKit/IOUSBHostInterface/GetFrameNumber",
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  "role" : "Instance Method",
  "symbol" : {
    "kind" : "Instance Method",
    "modules" : [
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    "preciseIdentifier" : "c:@S@IOUSBHostInterface@F@GetFrameNumber#*k#S0_#"
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  "title" : "GetFrameNumber"
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-->

# GetFrameNumber

Gets the current frame number of the USB controller.

```
virtual kern_return_t GetFrameNumber(uint64_t *frameNumber, uint64_t *theTime);
```

## Parameters

`frameNumber`

A pointer to a variable. On return, this variable contains the current frame number.

`theTime`

A pointer to a variable. On return, this variable contains the current time.

## Return Value

<doc://com.apple.documentation/documentation/DriverKit/kIOReturnSuccess> on success, or another value if an error occurs. See <doc://com.apple.documentation/documentation/DriverKit/error-codes>.

## Discussion

This method returns the current frame number of the USB controller, omitting the microframe. Use this information to schedule future isochronous requests.

---

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