$regfile = "m16def.dat"
$crystal = 8000000
$lib "lcd4busy.lib"

Const _lcdport = Portb
Const _lcdddr = Ddrb
Const _lcdin = Pinb

Const _lcd_e = 3
Const _lcd_rs = 2
Const _lcd_rw = 1

Config Twi = 100000
Config Sda = Portc.1
Config Scl = Portc.0
I2cinit

Config Lcd = 16 * 2

Dim X As String * 16
Dim Y As String * 16

Dim H As Byte , L As Byte
Dim C As Byte , I As Byte , S As String * 1 , Bank1 As Byte , Bank0 As Byte , Adrr As Word
Dim Lsb As Byte

Declare Sub Write_eeprom(byval Adresa As Word , Byval Value As Byte)
Declare Sub Read_eeprom(byval Adresa As Word , Value As Byte)

X = "Pokus s EEPROM  "

Cls
Lcd X
Lowerline


'zápis obsahu X(string *16) do EEPROM24C256

' Bank1 = 0...127(127 x 256 = 32512)
' Bank0 = 0...15 (15 x 16 + 15 =  255)
' 32512 + 255 = 32767 tj. &H7FFF

Bank1 = 0                                                   'stránka po 256byte
Bank0 = 10                                                  'stránka po 16byte

Bank0 = Bank0 * 16

For I = 0 To 15
   S = Mid(x , I , 1)
   C = Asc(s)
   Lsb = Bank0 + I
   Adrr = Makeint(lsb , Bank1)
   Call Write_eeprom(adrr , C)
Next I

Locate 2 , 1

'čtení z EEPROM a uložení do Y
Bank1 = 0
Bank0 = 10

Bank0 = Bank0 * 16

For I = 0 To 15
   Lsb = Bank0 + I
   Adrr = Makeint(lsb , Bank1)
   Call Read_eeprom(adrr , C)
   Y = Y + Chr(c)
Next I



'výpis obsahu Y na LCD
Lcd Y


Do
   Wait 1
Loop


'podprogramy
Sub Write_eeprom(byval Adresa As Word , Byval Value As Byte)

 H = High(adresa)
 L = Low(adresa)

 I2cstart
 I2cwbyte &B10101110                                        'adresa 24C256(zápis)
 I2cwbyte H
 I2cwbyte L
 I2cwbyte Value
 I2cstop
 Waitms 10
End Sub

Sub Read_eeprom(byval Adresa As Word , Value As Byte)

 H = High(adresa)
 L = Low(adresa)

 I2cstart
 I2cwbyte &B10101110                                        'adresa 24C256(zápis)
 I2cwbyte H
 I2cwbyte L
 I2crepstart
 I2cwbyte &B10101111                                        'adresa 24C256(čtení)
 I2crbyte Value , Nack
 I2cstop
 Waitms 10
End Sub

End