Please help with code for DS18B20

[fratello]

I try to read the serial number of my DS18B20 sensor with this code :

TRISA= %11110000 ' RA0..3=Outputs RA4=Input
TRISB= %00000111 ' RB0..RB2=Inputs, RB3..RB7=Outputs
CMCON=7 ' Disable comparators

DEFINE LCD_DREG PORTB ' LCD on port B
DEFINE LCD_DBIT 4 ' Data bits B4..B7
DEFINE LCD_RSREG PORTA ' RS on PORTA
DEFINE LCD_RSBIT 1 ' RS on A1
DEFINE LCD_EREG PORTA ' E on PORTA
DEFINE LCD_EBIT 0 ' E on A0
DEFINE LCD_BITS 4 ' LCD 4 bit mode
DEFINE LCD_LINES 2 ' 2 line LCD display

DQ Var PORTA.4 ' One-wire data pin
i Var Byte
Temp Var Byte
ReadRom Con $33

Pause 500
LCDOUT $FE, 1, $FE, $0C ' Clear display, cursor off
Pause 250

Main

OWOut DQ, 1, [ReadRom]
for i = 0 to 7
OWIn DQ, 0, [Temp]
LcdOut $FE, $80, Hex Temp
Next
LcdOut $FE, $14
LcdOut $FE, $14
Pause 1000
GoTo Main


but on display appears only "A7". What I do wrong ? Thanks !