Initialization Code in embedded system

Initialization Code in embedded system
initialization Code number of task, which can be grouped s intial Hardware configuration,
diagnostics and booting.

Initial Hardware Configuration : It involves setting up the target system so that it can boot an image.
example Memory system require reorganisation of memory map.

Diagnostics : This are often embedded in the initialization code, It test the system by execrising the harware target ti check
if target is in working order, also track down standard system related issues. Its primary purpose is fault identification and
isolation.

Booting : It involves leading and image and handing control over to that image. Booting an image is final phase but we need to
load it. Loading an image involves anything from copying an entire program include code and data in RAM, to just Copying a data area
containing volatile variable in RAM.

Read 2 : Interrupt Controller Notes (ARM Sys Dev Guide)

What is an interrupt controller ?
When a peripheral or device require attention, it raises as interrupt to the processor. An interrupt controller
provide a programmable governing policy that allows software to determine which peripheral or device can
intrrupt the process at any specific time by setting the appropriate bits in the interrupt controller
register.

There two kind of interrupt controller available for ARM processor
1. Standard interrupt controller
2. Vector interrupt controller

Read 1 : ARM Dev guide (About memory)

• The cache is placed between main memory and core. A cache provide an overall increase in the performance but with a loss of predictable execution time

• What is s memory width ?

The memory width is the number of bits the memory returns on each access - typically 8,16,32 or 64 bits. The memory width has a direct effort on the overall performance and cost ratio.

• Type of memory are being used
• ROM : Read only memory. to hold date which require no update or correction.
• Flash ROM : Can be written to as well as red, but it is slow to write so you should not use it for holding dynamic data. Its main use is for holding the device firmware or storing longterm data.
• Dynamic RAM : Most commonly use RAM for devices, lowest cost per MB, it need to have its storage all refreshed and given a new electronic charge every few mili-second, so need DRAM controller before using members.
• Synchronous Dynamic RAM : Runs on higher clock speed than conventional memory. It sync itself with processor because it is clocked.