Device Drivers explained in hardware talk.

theKbStockpiler · 01-28-2012, 07:23 AM

What's the relation to a Driver and the devices P.I.C/Processor instruction set.

Is half of a Device Driver a program in the P.I.Cs instruction set or Micro code? If this is true how are these commands converted to system calls?

Thanks in advance!

onebuck · 01-28-2012, 08:28 AM

Hi,

Quote:

Originally Posted by theKbStockpiler

What's the relation to a Driver and the devices P.I.C/Processor instruction set.

Is half of a Device Driver a program in the P.I.Cs instruction set or Micro code? If this is true how are these commands converted to system calls?

Thanks in advance!

If I understand your query then you are not relating the device driver(module) with the device firmware properly.

Device driver/Module is the layer between the kernel and the device firmware. Now the device firmware is the device's control program or handling of that local hardware by the devices interface hardware. Device firmware can be changed to improve device operations for actions and intercommunication with external handlers;

Quote:

Firmware;
In electronic systems and computing, firmware is a term often used to denote the fixed, usually rather small, programs and/or data structures that internally control various electronic devices. Typical examples of devices containing firmware range from end-user products such as remote controls or calculators, through computer parts and devices like hard disks, keyboards, TFT screens or memory cards, all the way to scientific instrumentation and industrial robotics. Also more complex consumer devices, such as mobile phones, digital cameras, synthesizers, etc., contain firmware to enable the device's basic operation as well as implementing higher-level functions.

HTH!

theKbStockpiler · 01-29-2012, 04:33 AM

Does not every Cpu on any type of Device have both an Instruction Set and Firmware/Microcode? If a Driver is the layer between Firmware/Micorcode and the Kernel ,what happened to the Instruction Set?

I thought that P.I.C as in 'Peripheral Interface Controller' was the generic name for a separate device attached to another 'main' cpu/processor and that the other P.I.C was 'Perfectly Independent Computer'.So what is the correct term for the former?

onebuck · 01-29-2012, 12:17 PM

Hi,

Quote:

PIC;

PIC is a family of modified Harvard architecture microcontrollers made by Microchip Technology, derived from the PIC1650[1][2][3] originally developed by General Instrument's Microelectronics Division. The name PIC initially referred to "Peripheral Interface Controller".[4][5]
PICs are popular with both industrial developers and hobbyists alike due to their low cost, wide availability, large user base, extensive collection of application notes, availability of low cost or free development tools, and serial programming (and re-programming with flash memory) capability.
Microchip announced on September 2011 the shipment of its ten billionth PIC processor.[6]

PIC was originally named Peripheral Interface Controller. Now it is considered to be a micro-controller that is programmable. The PIC is widely used in the electronic appliance industry for the reason of adaptability by reprogramming.

The instruction set for which? The PIC or the main system CPU arch system?

Each PIC manufacture has independent instructions set. Look at in this way: The PIC controls the device and operations for that device. Say a printer. The Print driver(module) controls the flow between the kernel and the PIC firmware. The two use different instruction sets. You seem to fail to realize the two systems (independent) have instruction sets for the separate system CPU and one instruction set (much smaller set) for micro-controller on the device.

Plus do not confuse the PIC (Programmable Interrupt Controller) with a PIC micro-controller. The former being a hardware device to control hardware interrupts in a system.

HTH!