I need to convert the entered real number into binary through assembler. I have this same code, only with integers and it works, but not here. When I enter with a period, e.g. 3.1 throws an error and stops the program, and when I enter with a comma, e.g. the 3,1 console just sits there and nothing happens.

includelib legacy_stdio_definitions.lib
includelib ucrt.lib

EXTERN printf: PROC
EXTERN scanf: PROC
EXTERN exit: PROC

.data
unos BYTE "Unesite dva realna broja: ", 0              
ispis BYTE "Broj 1: %f (binarno): %s nBroj 2: %f (binarno): %s n", 0  
formatStr BYTE "%f", 0                                 
a REAL4 ?                                              
b REAL4 ?                                              
binBr1 BYTE 33 DUP(?)                                    
binBr2 BYTE 33 DUP(?)                                   

.code
public asmReal

konverBin proc
    push rbx                                            
    mov rbx, rdi                                        
    mov ecx, 32                                         

convertLoop:
    shl eax, 1                                          
    mov byte ptr [rbx], '0'                             
    adc byte ptr [rbx], 0                               
    add rbx, 1                                          
    loop convertLoop                                    

    mov byte ptr [rbx], 0                                       
    pop rbx                                             
    ret         
konverBin endp


asmReal proc
    lea     rcx, unos                                   
    call    printf                                      

input_a:
    lea     rcx, formatStr                              
    lea     rdx, a                                      
    call    scanf                                       
    cmp     eax, 1                                      
    jne     input_a                                    

input_b:
    lea     rcx, formatStr                              
    lea     rdx, b                                      
    call    scanf                                       
    cmp     eax, 1                                      
    jne     input_b                                     


    lea     rdi, binBr1
    mov     eax, dword ptr [a]
    call    konverBin


    lea     rdi, binBr2
    mov     eax, dword ptr [b]
    call    konverBin


    mov     rcx, OFFSET ispis
    movss   xmm0, dword ptr [a]                         
    movss   xmm1, dword ptr [b]                         
    lea     r8, binBr1
    lea     r9, binBr2
    call    printf

    xor     ecx, ecx                                    
    call    exit                                        

asmReal endp
END

This is the error and exception when working with period (e.g. 3.1):

Exception thrown at 0x00007FFD529CB524 (ucrtbase.dll) in nekoeko.exe: 0xC0000005: Access violation reading location 0xFFFFFFFFFFFFFFFF.

In stdio.h:

#else
{
    return __stdio_common_vfprintf(_CRT_INTERNAL_LOCAL_PRINTF_OPTIONS, _Stream, _Format, _Locale, _ArgList);
}
#endif