Driving LED's using MCP23S17(SPI) on Arduino!

//#define SCK  13
//#define MOSI  11
//#define MISO  12
//#define SS 10
#include <SPI.h>

#define MCP23S17 B01000000  // MCP23017 SPI Address (Not used in this sketch)
#define IOCON   0x0A        // MCP23017 Config Reg.
#define IODIRA  0x00        // MCP23017 address of I/O direction
#define IODIRB  0x01        // MCP23017 1=input
#define IPOLA   0x02        // MCP23017 address of I/O Polarity
#define IPOLB   0x03        // MCP23017 1= Inverted
#define GPIOA   0x12        // MCP23017 address of GP Value
#define GPIOB   0x13        // MCP23017 address of GP Value
#define GPINTENA  0x04      // MCP23017 IOC Enable
#define GPINTENB  0x05      // MCP23017 IOC Enable
#define INTCONA 0x08        // MCP23017 Interrupt Cont
#define INTCONB 0x09        // MCP23017 1= compair to DEFVAL(A or B) 0= change
#define DEFVALA 0x06        // MCP23017 IOC Default value
#define DEFVALB 0x07        // MCP23017 if INTCONA set then INT. if diff.
#define GPPUA   0x0C        // MCP23017 Weak Pull-Ups
#define GPPUB   0x0D        // MCP23017 1= Pulled HIgh via internal 100k
#define OLATA   0x14
#define OLATB   0x15
#define INTFA   0x0E
#define INTFB   0x0F
#define INTCAPA 0x10
#define INTCAPB 0x11

const int slaveSelectPin = 10; //アクティブLOW

void setup() {
  // set the slaveSelectPin as an output:
  pinMode (slaveSelectPin, OUTPUT);
  // initialize SPI:
  SPI.begin();

  //IOCON設定(SEQOPのみDisable→0x20)
  writeData(IOCON,0x20);
  writeData(IOCON+1,0x20);

  //IODIRA,B設定(0で出力,1で入力)
  writeData(IODIRA,0x00);
  writeData(IODIRB,0x00);

}

void loop()
{
  //GPIOB設定
  writeData(GPIOB,0xff);
  delay(300);
  writeData(GPIOB,0x00);
  delay(300);
}

void writeData(uint8_t addr,uint8_t data)
{
  digitalWrite(slaveSelectPin,LOW);
  SPI.transfer(MCP23S17);
  SPI.transfer(addr);
  SPI.transfer(data);
  digitalWrite(slaveSelectPin,HIGH);
}