Doubt regarding the volatile keyword

What i understood is
(1)volatile unsigned char * ADC_address;
---ADC_address is a pointer which stores a volatile unsigned character .

(2)volatile unsigned int ADC_voltage = 0;
---ADC_voltage is volatile unsigned integer variable ,

(3)volatile unsigned char * ADC_REAL_ADDRESS;
ADC_REAL_ADDRESS = (volatile unsigned char *)STA_MEMORY_BASE;
---Typecasting STA_MEMORY_BASE to volatile unsigned char pointer and assigned to ADC_REAL_ADDRESS.

If I wrong means please correct me.

What i don't understood is
(4)Can anyone explain the below statements
#define PINSEL_BASE_ADDR 0xE002C000
#define PINSEL0 (*(volatile unsigned long *)(PINSEL_BASE_ADDR + 0x00))

what I understood is (volatile unsigned long *)(PINSEL_BASE_ADDR + 0x00) in this statement (PINSEL_BASE_ADDR + 0x00) is type casted to volatile unsigned long pointer. But (*(volatile unsigned long *)(PINSEL_BASE_ADDR + 0x00)) , what is for the starting star(dereferencing operator) after first bracket.

Your first three points are correct.

Quote:

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Originally Posted by 2001goran

(*(volatile unsigned long *)(PINSEL_BASE_ADDR + 0x00)) , what is for the starting star(dereferencing operator) after first bracket.

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You already know what it is - it's the dereferencing operator. This statement is saying "take PINSEL_BASE_ADDR, cast it to be a volatile unsigned long pointer, and then dereference it to give the unsigned long located there". In other words, using "PINSEL0" in your code read the value at PINSEL_BASE_ADDR (i.e. at 0xE002C000).

Also cross-posted
Doubt regarding the volatile keyword - Dev Shed