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  "title" : "HwProgramMCR"
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# HwProgramMCR

Configure the setings for the device’s modem control register (MCR).

```
virtual kern_return_t HwProgramMCR(bool dtr, bool rts);
```

## Parameters

`dtr`

A Boolean value indicating whether to set or clear the data-terminal-ready bit. If the value is `YES`, set the bit; otherwise, clear it.

`rts`

A Boolean value indicating whether to set or clear the request-to-send bit. If the value is `YES`, set the bit; otherwise, clear it.

## 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

Override this method and use it to program your hardware with the specified information.

---

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