Device Drivers

Describing Device Drivers

• A device driver refers to software

• It is used for the following reasons:

  • Monitoring devices attached to a computer
  • Informing the system of any operations performed
• In other words, a driver is a translator between a hardware device and any application

Describing Device Controllers

• A device controller refers to physical hardware
• It is used for handling incoming and outgoing CPU signals

• For example:

  • Every device is connected to a computer via plug
  • The plug is connected to a device controller

• A device controller is used for the following:

  • Converts a serial bit stream to a block of bytes
  • Performs error correction as required
• All controllers are connected to the CPU via the common bus

Illustrating Device Controllers

• The memory is connected to a memory controller
• The monitor is connected to a video controller
• The keyboard is connected to a keyboard controller
• The disk drive is connected to a disk controller
• The USB drive is connected to a USB controller

Defining the Life Cycle of Device Controllers

1. A device controller receives data from a connected device

2. The device controller stores that data temporarily

   • It is stored in a special purpose register
   • This registed is called a local buffer
   • Implying, the local buffer is inside the controller
3. The device controler interprets the signal for the device driver
4. The device driver receives the interpreted signal

References

• Defining the Differences between Drivers and Controllers