rGPEDAT not read write ???

MAHDIKHAFAN
Hello
iam new in mini2440
i want use camera pins for make i2c software ,pins 15,14 GPE but after set
pins i cannot read ,write on pins by rGPEDAT
i use for set and clear pins this code 

//Ports  : GPE15  GPE14 
//Signal : IICSDA IICSCL 
//Binary :  10     10
rGPECON = 0xa0000000;
rGPEUP  = 0xffff;     // The pull up function is disabled GPE[15:0]

#define  read_gpio_bit(x)  ((rGPEDAT & (1<<(x))) ? 1 : 0)
#define  write_gpio_bit_set(x)  (rGPEDAT |= 1<<(x))
#define  write_gpio_bit_clear(x)  (rGPEDAT &= ~(1<<(x)))


what is meaning binary for port 01 or 10 or 11 ,..... ? this use for set
pin to output , input,....


thnx for help ?

MAHDIKHAFAN
also i use 2440test source