I am getting my MV values in ADC as 268 but for my requirements it should read vge equivalent to 1.31 but I am getting only 0.8 with Vref 3.3v.Can any help me with my configuration is correct .What is my mistake here please

[SRAM.11]

/* MAIN.C file

 * 

 * Copyright (c) 2002-2005 STMicroelectronics

 */

#include "stm8s.h"

#include "stm8s_clk.h"

#include "stm8s_adc1.h"

void Clk_Config(void);

void ADC_Config(void);

void ADC_Read(uint16_t *MV);

main()

{

unsigned short MV;

Clk_Config();

ADC_Config();

while (1)

 {

ADC_Read(&MV);

}

}

void Clk_Config()

{

CLK_DeInit();

CLK_HSECmd(DISABLE);

CLK_LSICmd(DISABLE);

CLK_HSICmd(ENABLE);

while(CLK_GetFlagStatus(CLK_FLAG_HSIRDY) == FALSE);

CLK_ClockSwitchCmd(ENABLE);

CLK_HSIPrescalerConfig(CLK_PRESCALER_HSIDIV2);

CLK_SYSCLKConfig(CLK_PRESCALER_CPUDIV4);

CLK_ClockSwitchConfig(CLK_SWITCHMODE_AUTO, CLK_SOURCE_HSI, 

DISABLE, CLK_CURRENTCLOCKSTATE_ENABLE);

CLK_PeripheralClockConfig(CLK_PERIPHERAL_ADC, ENABLE);

}

void ADC_Config()

{

ADC1_DeInit();

ADC1_Init(ADC1_CONVERSIONMODE_CONTINUOUS, 

 ADC1_CHANNEL_5,

 ADC1_PRESSEL_FCPU_D2, 

 ADC1_EXTTRIG_GPIO, 

 DISABLE, 

 ADC1_ALIGN_RIGHT, 

 ADC1_SCHMITTTRIG_CHANNEL5, 

 DISABLE);

  ADC1_Cmd(ENABLE);

  ADC1_ITConfig(ADC1_IT_EOCIE, ENABLE);

}

void ADC_Read(uint16_t *MV)

{

  ADC1_StartConversion();

  while (!ADC1_GetFlagStatus(ADC1_FLAG_EOC))

  {

    // Wait for conversion to complete

  }

 *MV= ADC1_GetConversionValue();

}