Write value on Register not shown

​​Hi, I just build a qsys system as shown below

where I just wana write and read data to a simple 8 bit register which I wrote and instantiated in qsys as usererg8bit. Here is the verilog HDL code for that

module userreg8bit(
input write,
input [7:0] writedata,
input read,
output [7:0] readdata,
input clk,
input reset
);
 
reg [7:0] Regreaddata;
 
assign readdata=Regreaddata;
 
always @ (posedge clk)
	begin
		if(reset)
			begin
				Regreaddata<=0;
			end
		else if(write)
			begin
				if(read)
					begin
						Regreaddata<=writedata;
					end
			end
	end
 
endmodule

Now I wrote a C application for HPS as .

#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <stdint.h>
#include <fcntl.h> 
#include <sys/mman.h>
#include <sys/types.h>
#include <sys/stat.h>
#include "C:\altera\15.1\embedded\ip\altera\hps\altera_hps\hwlib\include\hwlib.h"
#include "C:\altera\15.1\embedded\ip\altera\hps\altera_hps\hwlib\include\soc_cv_av\socal\socal.h"
#include "C:\altera\15.1\embedded\ip\altera\hps\altera_hps\hwlib\include\soc_cv_av\socal\hps.h" 
/*#include "C:\altera\15.1\embedded\ip\altera\hps\altera_hps\hwlib\include\soc_cv_av\socal\alt_gpio.h"*/
#include "D:\masterarbeit3\HPSFPGAFIFO\hps_0.h"
 
#define REG_BASE 0xFF200000      /*LWFPGA SLAVE Address*/
#define REG_SPAN 0x00200000    /*LWFPGA SLAVE SPAN*/
 
volatile unsigned char *reg_addr; /*this is the pointer that writes to the register. This is our write input*/
void* virtual_base; /*pointer to open device memory file*/
 
int main ()
{
	
int fd = EXIT_FAILURE;	
int value; /*this is input value to the register*/
unsigned char regvalue;
 
printf("Please enter a number from 1 to 15: ");
scanf("%d",&value);
printf("you entered the value :%d",value);	
 
fd=open("/dev/mem",(O_RDWR|O_SYNC));
if (fd < 0) {
		perror("open");
		exit(EXIT_FAILURE);
			}
 
virtual_base=mmap(NULL,REG_SPAN,(PROT_READ|PROT_WRITE),MAP_SHARED,fd,REG_BASE);
 
reg_addr = (unsigned char *) (virtual_base+USERREG8BIT_0_BASE); 
 
/*writing the value*/
*reg_addr=value;
 
/*reading the value back*/
regvalue=*reg_addr;
printf("%c\n",regvalue);
 
return 0;
}

Here is my make file

#
TARGET = HPSFPGAFIFO
 
#
CROSS_COMPILE = arm-linux-gnueabihf-
ALT_DEVICE_FAMILY ?= soc_cv_av 
CFLAGS := -g $(OFLAG) -Wall -Werror -std=c99 $(MULTILIBFLAGS) -I$(HWLIBS_ROOT)/include -I$(HWLIBS_ROOT)/include -D$(ALT_DEVICE_FAMILY) 
 
ALL_HWLIBS_SRC = $(wildcard $(HWLIBS_ROOT)/src/hwmgr/*.c) $(wildcard $(HWLIBS_ROOT)/src/hwmgr/$(ALT_DEVICE_FAMILY)/*.c $(wildcard $(HWLIBS_ROOT)/src/utils/*.c)) 
LDFLAGS =  -g -Wall  
CC = $(CROSS_COMPILE)gcc
ARCH= arm
 
 
build: $(TARGET)
$(TARGET): HPSFPGAFIFO.o 
	$(CC) $(LDFLAGS)   $^ -o $@  
%.o : %.c
	$(CC) $(CFLAGS) -c $< -o $@
 
.PHONY: clean
clean:
	rm -f $(TARGET) *.a *.o *~

My c code compiled successfully now when I run my C application on Cyclone V arrow sockit board, it takes data input from user but after that doesn't show me the output. Any ideas where am I wrong?