diff --git a/firmware.asm b/firmware.asm
index a12cdce..8e391b1 100644
--- a/firmware.asm
+++ b/firmware.asm
@@ -46,14 +46,21 @@
 .equ POLLING_STATE = 0x03
 .equ COMPLETION_STATE = 0x04
 
-.equ TRUE = 1
-.equ FALSE = 0
+;
+; SW Flags states constants
+.equ SW_FLAG_1 = 0xe0
+.equ SW_FLAG_2 = 0xd0
+.equ SW_FLAG_3 = 0xb0
+.equ SW_FLAG_4 = 0x70
 
 .macro init_stack_p         ; Setup stack pointer
   ldi @0, low(@1)
   out SPL, @0
 .endm
 
+;
+; @0 - I/O Register
+; @1 - Data to write
 .macro outi                 ; Out to i/o reg
   push r16
   ldi r16, @1
@@ -71,6 +78,8 @@
   pop r16
 .endm
 
+;
+; @0 - New state
 .macro set_state
   push r16
   lds r16, CURRENT_STATE_ADDRESS
@@ -80,13 +89,6 @@
   pop r16
 .endm
 
-.macro set_sw_flag
-  push r19
-  ldi r19, @0
-  sts SW_FLAGS_ADDRESS, r19
-  pop r19
-.endm
-
 .dseg                       ; Data segment
 .org	SRAM_START
 
@@ -105,7 +107,7 @@ SW_FLAGS_ADDRESS: .byte 0x01
 ;
 ; Setup vectors
 rjmp start                  ; Program start at RESET vector
-reti                        ; External Interrupt Request 0
+reti                        ; External Interrupt Request 0 / inactive
 rjmp PCINT0_vect            ; Pin Change Interrupt Request 0 / active
 reti                        ; Pin Change Interrupt Request 1 / inactive
 reti                        ; Watchdog Time-out / inactive
@@ -127,7 +129,7 @@ reti                        ; USI Overflow / inactive
 PCINT0_vect:                 
   push r17
   push r18
-
+  ; // TODO update flag only in POLLING state of MCU
   in r18, SREG
   in r17, PINA              ; Load current pins status of PINA
   andi r17, 0xf0            ; Get pins status of only buttons
@@ -144,7 +146,6 @@ reti
 start:
   init_stack_p r16, RAMEND  ; Init stack pointer of MCU
   set_state INIT_STATE      ; Turn MCU state to initialization
-  set_sw_flag 0x00
 loop:                       ; Program loop
   lds r16, CURRENT_STATE_ADDRESS
   init:                     ; Init state
@@ -159,7 +160,7 @@ loop:                       ; Program loop
     
     lds r18, SW_FLAGS_ADDRESS
     led_1:
-      cpi r18, 0xe0
+      cpi r18, SW_FLAG_1
       brne led_off_1
       led_on_1:
         sbi LED_PORT, 0
@@ -167,7 +168,7 @@ loop:                       ; Program loop
       led_off_1:
         cbi LED_PORT, 0
     led_2:
-      cpi r18, 0xd0
+      cpi r18, SW_FLAG_2
       brne led_off_2
       led_on_2:
         sbi LED_PORT, 1
@@ -175,7 +176,7 @@ loop:                       ; Program loop
       led_off_2:
         cbi LED_PORT, 1
     led_3:
-      cpi r18, 0xb0
+      cpi r18, SW_FLAG_3
       brne led_off_3
       led_on_3:
         sbi LED_PORT, 2
@@ -183,7 +184,7 @@ loop:                       ; Program loop
       led_off_3:
         cbi LED_PORT, 2
     led_4:
-      cpi r18, 0x70
+      cpi r18, SW_FLAG_4
       brne led_off_4
       led_on_4:
         sbi LED_PORT, 3
diff --git a/firmware.hex b/firmware.hex
index ad57f48..ba9a2b8 100644
--- a/firmware.hex
+++ b/firmware.hex
@@ -1,28 +1,28 @@
 :020000020000FC
 :100000001CC018950EC01895189518951895189538
 :100010001895189518951895189518951895189578
-:1000200018951F932F932FB719B3107F84D0109377
+:1000200018951F932F932FB719B3107F7FD010937C
 :1000300062002FBF2F911F9118950FED0DBF0F93E9
 :1000400000916000009361000F9301E00093600055
-:100050000F910F913F9330E0309362003F910091F8
-:100060006000013061F44FD00F9300916000009365
-:1000700061000F9302E0009360000F910F91023036
-:10008000B1F420916200203E11F4D89A01C0D898B2
-:10009000203D11F4D99A01C0D998203B11F4DA9A85
-:1000A00001C0DA98203711F4DB9A01C0DB980330E5
-:1000B00001F4043001F4D3CF1F932F933F934F9358
-:1000C0004BB30F9301EF0BBB0F9135D011E033E031
-:1000D00020EF110F210F2BBB2ED03A95C9F70F93AC
-:1000E00008EF0BBB0F9127D018E033E020EF1695F7
-:1000F000210F2BBB20D03A95C9F74BBB4F913F91B5
-:100100002F911F91089510D008D001D0089516E0C6
-:10011000D3DF1A95E9F71BD0089500E10BBF00EF7C
-:1001200002BB0027789408950FE00ABB02950BBB31
-:10013000BA9AC29808952F933F9321E43FEE3A95DF
-:10014000F1F72A95E1F700003F912F9108958F93E1
-:100150009F9324E683EC99E00197F1F72A95D1F774
-:1001600024E69F918F9108954D656D6F7279206C93
-:1001700065642067616D652E205772697474656EC1
-:1001800020627920536572676579205961726B6FBF
-:0C019000762032372E30392E32303231DA
+:100050000F910F9100916000013061F44FD00F9328
+:1000600000916000009361000F9302E00093600034
+:100070000F910F910230B1F420916200203E11F4F3
+:10008000D89A01C0D898203D11F4D99A01C0D998C6
+:10009000203B11F4DA9A01C0DA98203711F4DB9A88
+:1000A00001C0DB98033001F4043001F4D3CF1F9377
+:1000B0002F933F934F934BB30F9301EF0BBB0F91D4
+:1000C00035D011E033E020EF110F210F2BBB2ED0E4
+:1000D0003A95C9F70F9308EF0BBB0F9127D018E0A3
+:1000E00033E020EF1695210F2BBB20D03A95C9F7AE
+:1000F0004BBB4F913F912F911F91089510D008D085
+:1001000001D0089516E0D3DF1A95E9F71BD00895C2
+:1001100000E10BBF00EF02BB0027789408950FE0C9
+:100120000ABB02950BBBBA9AC29808952F933F93CE
+:1001300021E43FEE3A95F1F72A95E1F700003F916F
+:100140002F9108958F939F9324E683EC99E0019774
+:10015000F1F72A95D1F724E69F918F9108954D6587
+:100160006D6F7279206C65642067616D652E205714
+:1001700072697474656E206279205365726765795F
+:10018000205961726B6F762032372E30392E323023
+:0201900032310A
 :00000001FF