MVC architecture question for Mac application

- (void) notifyContentHasChanged:(NSInteger) block {
    NSString *str;
    str = [NSString stringWithFormat:@"Block Written Successfully: %dn", block];
    [data insertText:str];
}

Controller * c = [[Controller alloc] init];
while (USB_SUCCESS(status)){
    DfuBlockCnt++;
    printf("nBlocks Written Successfully: %d",DfuBlockCnt);
    [c notifyContentHasChanged:DfuBlockCnt];
}