/// <summary>
/// reads a byte from the specified port
/// </summary>
/// <param name="port">port address (2 bytes)</param>
/// <returns>the data byte from the port</returns>
public int Read(int port)
{
lock (portLock)
{
int ret = 0;
for (int i = 0; i < ADDR_PINS.Length; i++)
{
int j = 1 << i;
if ((port & j) > 0)
{
GPIO.SetPinLevel(ADDR_PINS[i], 1);
}
else
{
GPIO.SetPinLevel(ADDR_PINS[i], 0);
}
}
GPIO.SetPinLevel(IOR_PIN, 0);
for (int i = 0; i < DATA_PINS.Length; i++)
{
int pin = DATA_PINS[i];
bool level = GPIO.GetPinLevel(pin);
ret = level ? ret | (1 << i) : ret & ~(1 << i);
}
GPIO.SetPinLevel(IOR_PIN, 1);
return(ret);
}
}
/// <summary>
/// writes a byte to the specified port
/// </summary>
/// <param name="port">port address</param>
/// <param name="data">port data</param>
public void Write(int port, int data)
{
lock (portLock)
{
for (int i = 0; i < DATA_PINS.Length; i++)
{
GPIO.SetPinDir(DATA_PINS[i], true);
int j = 1 << i;
if ((data & j) > 0)
{
GPIO.SetPinLevel(DATA_PINS[i], 1);
}
else
{
GPIO.SetPinLevel(DATA_PINS[i], 0);
}
}
for (int i = 0; i < ADDR_PINS.Length; i++)
{
int j = 1 << i;
if ((port & j) > 0)
{
GPIO.SetPinLevel(ADDR_PINS[i], 1);
}
else
{
GPIO.SetPinLevel(ADDR_PINS[i], 0);
}
}
GPIO.SetPinLevel(IOW_PIN, 0);
GPIO.SetPinLevel(IOW_PIN, 1);
for (int i = 0; i < DATA_PINS.Length; i++)
{
int pin = DATA_PINS[i];
GPIO.SetPinDir(pin, false);
}
}
}