FTDI LibFT4222 - Page 70

Application Note
AN_329 User Guide For LibFT4222
Version 1.5
Document Reference No.: FT_001060 Clearance No.: FTDI#406
69
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Parameters:
ftHandle
Handle of the device.
portNum
One of the following GPIO port:
 GPIO_PORT0
 GPIO_PORT1
 GPIO_PORT2
 GPIO_PORT3
events
Pointer to the buffer that receives the values of the trigger event queue. The
value of events will be:
 GPIO_TRIGGER_RISING
 GPIO_TRIGGER_FALLING
 GPIO_TRIGGER_LEVEL_HIGH
 GPIO_TRIGGER_LEVEL_LOW
readSize
Number of bytes to read from trigger event queue.
sizeofRead
Pointer to a variable of type uint16 which receives the number of bytes read from
the queue.
Queue data is cleared after calling this function
For GPIO :
The trigger condition needs to be set by the function
FT4222_GPIO_SetInputTrigger
For Interrupt :
The trigger condition needs to be set by the function
FT4222_SetInterruptTrigger
Return Value:
FT4222_OK if successful, otherwise the return value is a FT error code.
Error code:
FT4222_DEVICE_NOT_OPENED: The initialization API is not called.
FT4222_GPIO_NOT_SUPPORTED_IN_THIS_MODE: GPIO function is not supported in mode 2 and
mode 3
Prerequisite:
FT4222_GPIO_Init
Example:
FT_HANDLE ftHandle = NULL;
FT_STATUS ftStatus;
FT4222_STATUS ft4222Status;
ftStatus = FT_OpenEx("FT4222 B",FT_OPEN_BY_DESCRIPTION, &ftHandle);
if (FT_OK != ftStatus)
{
// open failed
return;
}
GPIO_Dir gpioDir[4];
gpioDir[0] = GPIO_INPUT;
gpioDir[1] = GPIO_OUTPUT;
gpioDir[2] = GPIO_OUTPUT;
gpioDir[3] = GPIO_OUTPUT;
FT4222_GPIO_Init(ftHandle, gpioDir);
uint16 queueSize;
FT4222_GPIO_SetInputTrigger(ftHandle,
GPIO_PORT0,
(GPIO_Trigger)(GPIO_TRIGGER_LEVEL_HIGH |