PCF8584_DATA
writeb(PCF8584_ADDRESS, i2c + PCF8584_DATA);
writeb(CLK_4_43 | BUS_CLK_90, i2c + PCF8584_DATA);
writeb(addr + 1, i2c + PCF8584_DATA);
return readb(i2c + PCF8584_DATA);
writeb(addr, i2c + PCF8584_DATA);
return readb(i2c + PCF8584_DATA);
writeb(port, i2c + PCF8584_DATA);
return readb(i2c + PCF8584_DATA);