# i2c_compare_byte

## Description
Compares a device register to a byte value.  Communicates with the device
directly using the [I2C interface](i2c_interface.md).

## Properties
| Name | Required | Type | Description |
| :--- | :------: | :--- | :---------- |
| register | yes | string | Device register address expressed in hexadecimal.  Must be prefixed with 0x and surrounded by double quotes. |
| value | yes | string | Expected byte value expressed in hexadecimal.  Must be prefixed with 0x and surrounded by double quotes. |
| mask | no | string | Bit mask expressed in hexadecimal.  Must be prefixed with 0x and surrounded by double quotes.  Specifies which bits should be compared within the byte value.  Only the bits with a value of 1 in the mask will be compared. |

## Return Value
Returns true if the register contained the expected value, otherwise returns
false.

## Examples
```
{
  "comments": [ "Check if register 0xA0 contains 0xFF" ],
  "i2c_compare_byte": {
    "register": "0xA0",
    "value": "0xFF"
  }
}

{
  "comments": [ "Check if register 0x82 contains 0x40.",
                "Ignore the most significant bit." ],
  "i2c_compare_byte": {
    "register": "0x82",
    "value": "0x40",
    "mask": "0x7F"
  }
}
```