help for display set pixel and ADC reading functions

[jackcmos]

i am new learner try to do the following task:


The system required is to act as a simple oscilloscope, utilising a 256x256 display to graph the analogue inputs to a microcontroller.
The microcontroller is a 32 bit machine, big-endian. Memory addresses are directed to bytes, with 16 bit accesses limited to even addresses, and 32 bit accesses limited to multiples of 4.
The ADC has a resolution of 16 bits, and can do an A/D conversion in a single instruction
The memory map of the micro is as follows:

0x00000..0x0FFFF Code/data space
0x10000..0x1FFFF Display, 8 bits wide, mapped x first
0x20000..0x20001 A/D

You have been provided with the following function prototypes:

typedef unsigned short ushort;
typedef unsigned char ubyte;
void Display_Clear( void );
void Display_SetPixel( ushort x, ushort y, ubyte intensity );
short ADC_Read( void );

1) How might Display_SetPixel be coded?

//my code, but i think it might not correct.

void Display_SetPixel( ushort x, ushort y, ubyte intensity )
{
  
  int  DisplayBufferSize = (x * y);

unsigned  char  DisplayImage [DisplayBufferSize / 8];	


// here I assumed bytes describe the vertical stripes

	unsigned  char  * byte = &DisplayImage[x + (y / 8) * x];
	if (intensity)
		*byte |= 1 << (x % 8);
	else
		*byte &= ~(1 << (x % 8));
}

2) Write the code to plot the ADC readings on the display, to act as an oscilloscope. Please list any assumptions you have made about the system.

adc_result = (ReadADC()) / 2; 
Display_Clear();
//how to match the adc_result on to the display???
//please help!