Application Note
AN_329
User Guide For LibFT4222
Version 1.1
Issue Date: 2015-09-10
The application note is a guide for LibFT4222 based on D2XX. It
provides high-level and convenient APIs for FT4222H application
development.
Use of FTDI devices in life support and/or safety applications is entirely at the user’s risk,
and the user agrees to defend, indemnify and hold FTDI harmless from any and all
damages, claims, suits or expense resulting from such use.
Future Technology Devices International Limited (FTDI)
Unit 1, 2 Seaward Place, Glasgow G41 1HH, United Kingdom
Tel.: +44 (0) 141 429 2777 Fax: + 44 (0) 141 429 2758
Web Site: http://ftdichip.com
Copyright © 2015 Future Technology Devices International Limited
Application Note
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Table of Contents
1 Introduction .............................................................. 4
1.1 Overview .............................................................................5
1.2 Scope ..................................................................................7
2 Getting Started .......................................................... 8
3 Application Programming Interface (API) ............... 11
3.1 Typedefs............................................................................ 11
3.2 FT4222 General Functions ................................................. 11
3.2.1
Open and Close ............................................................................................ 11
3.2.2
Un-initialize ................................................................................................. 12
3.2.3
Set Clock ..................................................................................................... 12
3.2.4
Get Clock..................................................................................................... 13
3.2.5
Set Suspend Out .......................................................................................... 13
3.2.6
Set Wake Up/Interrupt .................................................................................. 13
3.2.7
Set Interrupt Trigger Condition....................................................................... 14
3.2.8
Get Max Transfer Size ................................................................................... 14
3.2.9
Set Event Notification .................................................................................... 15
3.2.10
Get Version .................................................................................................. 16
3.3 SPI Master Functions ........................................................ 17
3.3.1
SPI Master Init ............................................................................................. 17
3.3.2
SPI Master Set Lines ..................................................................................... 19
3.3.3
SPI Master Single Read ................................................................................. 19
3.3.4
SPI Master Single Write ................................................................................. 20
3.3.5
SPI Master Single Read and Write ................................................................... 20
3.3.6
SPI Master Multi Read and Write ..................................................................... 21
3.4 SPI Slave Functions ........................................................... 24
3.4.1
SPI Slave Init ............................................................................................... 26
3.4.2
SPI Slave Get Rx Status ................................................................................ 27
3.4.3
SPI Slave Read ............................................................................................. 27
3.4.4
SPI Slave Write ............................................................................................ 27
3.5 SPI General Functions ....................................................... 29
3.5.1
SPI Reset Transaction ................................................................................... 29
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3.5.2
SPI Reset .................................................................................................... 29
3.5.3
SPI Set Driving Strength ............................................................................... 30
3.6 I2C Master Functions ......................................................... 31
3.6.1
I2C Master Init ............................................................................................. 31
3.6.2
I2C Master Read ........................................................................................... 31
3.6.3
I2C Master Write .......................................................................................... 32
3.6.4
I2C Master Write Extension ............................................................................ 32
3.6.5
I2C Master Read Extension ............................................................................ 33
3.6.6
I2C Master GetStatus .................................................................................... 34
3.6.7
I2C Master Reset .......................................................................................... 35
3.7 I2C Slave Functions ........................................................... 36
3.7.1
I2C Slave Init ............................................................................................... 36
3.7.2
I2C Slave Get Address .................................................................................. 36
3.7.3
I2C Slave Set Address ................................................................................... 37
3.7.4
I2C Slave Get Rx Status ................................................................................ 37
3.7.5
I2C Slave Read ............................................................................................ 37
3.7.6
I2C Slave Write ............................................................................................ 38
3.7.7
I2C Slave Reset ............................................................................................ 38
3.8 GPIO Functions .................................................................39
3.8.1
GPIO Init ..................................................................................................... 39
3.8.2
GPIO Read ................................................................................................... 40
3.8.3
GPIO Write .................................................................................................. 40
3.8.4
GPIO Set Input Trigger .................................................................................. 41
3.8.5
GPIO Get Trigger Status ................................................................................ 42
3.8.6
GPIO Read Trigger Queue .............................................................................. 42
4 Contact Information ................................................ 44
Appendix A – Enumeration and Structure Definitions .. 45
Appendix B – References ............................................. 48
Document References ............................................................... 48
Acronyms and Abbreviations..................................................... 48
Appendix C – List of Tables & Figures .......................... 49
List of Tables............................................................................. 49
List of Figures ........................................................................... 49
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Appendix D – Revision History ..................................... 50
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1 Introduction
The FT4222H is a USB interface device which supports SPI and I2C communication
protocol. It is accompanied with the support library “LibFT4222” based on D2XX, which
provides high-level APIs to facilitate user application development. At the time of writing
support for Windows and Linux OS has been published. Android support uses a different
package also available from the FTDI website.
The FT4222H contains SPI/I2C configurable interfaces. The SPI interface can be
configured as master mode with single, dual, quad bits wide data transfer or slave mode
with single bit wide data transfer. The I2C interface can be configured as master or slave
mode.
User Application
LibFT4222
(SPI/I2C Library)
D2XX API
USB Bus driver
FTDI FT4222H chip
Figure 1.1 The software stack
Note that the Linux version of LibFT4222 has D2XX built-in.
The LibFT4222 sample code, release notes, and all necessary files can be downloaded
from the FTDI website at:
http://www.ftdichip.com/Products/ICs/FT4222H.html
The sample source code contained in this application note is provided as an example and
is neither guaranteed nor supported by FTDI.
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1.1 Overview
The FT4222H supports 4 operation modes to allow various I2C/SPI devices to be
connected to USB bus. The attachable device configuration for each mode is listed below:
Mode 0 (2 USB interfaces):
1 SPI master, SPI slave, I2C master, or I2C slave device
1 GPIO device
Mode 1 (4 USB interfaces):
SPI master connects up to 3 SPI slave devices
1 GPIO device
Mode 2 (4 USB interfaces):
SPI master connects up to 4 SPI slave devices
Mode 3 (1 USB interface):
1 SPI master, SPI slave, I2C master, or I2C slave device
In mode 0 and 3, the connected device can be a SPI/I2C master or slave, depending on
how an application developer initializes the FT4222H chip. Mode 1 and mode 2 are
designed to connect to multiple SPI slave devices.
The FT4222H can be configured with up to 4 GPIO pins for user applications in mode 0
and mode 1, but each pin is multiplexed with interrupt/suspend out/SPI slave select/I2C
functions as listed below:
gpio0 / ss1o / scl
gpio1 / ss2o / sda
gpio2 / ss3o / suspend out
gpio3 / wakeup/intr
If the FT4222H is initialized as an I2C device, with pins as shown above, the pins of gpio0
and gpio1 will be switched to scl and sda, and cannot be used as GPIO.
By default the pin for gpio2 is configured as suspend out, and the pin for gpio3 is
configured as wakeup/intr. Only those configured GPIO pins can support GPIO read/set
operation through the corresponding endpoint.
The following diagrams show the examples of FT4222H SPI/I2C master connections.
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Figure 1.2 Mode 0: FT4222H works as SPI master (quad mode)
Figure 1.3 Mode 0: FT4222H works as I2C master
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Figure 1.4 Mode 2: FT4222H works as SPI master
1.2 Scope
The guide is intended for developers who are creating applications, extending FTDI
provided applications or implementing FTDI’s applications for the FT4222H.
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2 Getting Started
A
LibFT4222
application
usually
starts
with
FT_CreateDeviceInfoList
and
FT_GetDeviceInfoList as a traditional D2XX application does. Under different chip modes,
FT_CreateDeviceInfoList reports a different number of interfaces as shown in the table
below.
Mode
Num of
Interfaces
0
2
Device Function
a. The first interface: it can be one of SPI master, SPI slave, I2C
master, or I2C slave device.
b. The second interface: GPIO device.
a. The first 3 interfaces: SPI master connects up to 3 SPI slaves.
1
4
2
4
a. SPI master connects up to 4 SPI slaves. Please refer figure 1.4.
FT4222H works as SPI master.
3
1
a. it can be one of SPI master, SPI slave, I2C master, or I2C slave
device.
b. The 4th interface: GPIO device.
Table 2.1 Chip mode and device functions
After opening the device with FT_Open, developers need to initialize the FT4222H device
as either SPI master, SPI slave, I2C master, or I2C slave. Different types of device
require different configurations. For more details, please refer the next chapter.
Following example code shows FT4222H works in SPI master mode.
Example#
include <windows.h>
#include <stdio.h>
#include <stdlib.h>
#include <vector>
#include <string>
#include "ftd2xx.h"
#include "LibFT4222.h"
std::vector< FT_DEVICE_LIST_INFO_NODE > g_FT4222DevList;
inline std::string DeviceFlagToString(DWORD flags)
{
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std::string msg;
msg += (flags & 0x1)? "DEVICE_OPEN" : "DEVICE_CLOSED";
msg += ", ";
msg += (flags & 0x2)? "High-speed USB" : "Full-speed USB";
return msg;
}
void ListFtUsbDevices()
{
DWORD numOfDevices = 0;
FT_STATUS status = FT_CreateDeviceInfoList(&numOfDevices);
for(DWORD iDev=0; iDev<numOfDevices; ++iDev)
{
FT_DEVICE_LIST_INFO_NODE devInfo;
memset(&devInfo, 0, sizeof(devInfo));
status = FT_GetDeviceInfoDetail(iDev,
&devInfo.Flags, &devInfo.Type, &devInfo.ID, &devInfo.LocId,
devInfo.SerialNumber, devInfo.Description, &devInfo.ftHandle);
if (FT_OK == status)
{
printf("Dev %d:\n", iDev);
printf("
Flags= 0x%x, (%s)\n", devInfo.Flags,
DeviceFlagToString(devInfo.Flags).c_str());
printf("
Type= 0x%x\n",
devInfo.Type);
printf("
ID= 0x%x\n",
devInfo.ID);
printf("
LocId= 0x%x\n",
devInfo.LocId);
printf("
SerialNumber= %s\n",
devInfo.SerialNumber);
printf("
Description= %s\n",
devInfo.Description);
printf("
ftHandle= 0x%x\n",
devInfo.ftHandle);
const std::string desc = devInfo.Description;
if(desc == "FT4222" || desc == "FT4222 A") {
g_FT4222DevList.push_back(devInfo);
}
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}
}
}
int main(int argc, char const *argv[])
{
ListFtUsbDevices();
if(g_FT4222DevList.empty()) {
printf("No FT4222 device is found!\n");
return 0;
}
FT_HANDLE ftHandle = NULL;
FT_STATUS ftStatus;
ftStatus = FT_OpenEx((PVOID)g_FT4222DevList[0].LocId,
FT_OPEN_BY_LOCATION, &ftHandle);
if (FT_OK != ftStatus)
{
printf("Open a FT4222 device failed!\n");
return 0;
}
ftStatus = FT4222_SPIMaster_Init(ftHandle,
SPI_IO_SINGLE, CLK_DIV_4, CLK_ACTIVE_LOW, CLK_LEADING, 0x01);
if (FT_OK != ftStatus)
{
printf("Init FT4222 as SPI master device failed!\n");
return 0;
}
// TODO:
//
Start to work as SPI master, and read/write data to an SPI slave
//
FT4222_SPIMaster_SingleWrite
//
FT4222_SPIMaster_SingleRead
//
FT4222_SPIMaster_SingleReadWrite
FT4222_Uninitialize(ftHandle);
FT_Close(ftHandle);
return 0;
}
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3 Application Programming Interface (API)
LibFT4222 supports SPI, I2C and GPIO communication using high-level APIs. In addition,
it provides chip configuration APIs, such as FT4222_SetClock.
After calling FT_Open, the FT4222H is required to be initialized by one of the following
initial functions:
FT4222_SPIMaster_Init
FT4222_SPISlave_Init
FT4222_I2CMaster_Init
FT4222_I2CSlave_Init
FT4222_GPIO_Init
The initialization functions help developers to switch the FT4222H into a specific mode.
At the end of the application, FT4222_Uninitialize should be called to release allocated
resources, before calling FT_Close.
All the APIs return an FT4222_STATUS, which extends FT_STATUS that is defined in the
D2XX driver. FT4222_STATUS defines additional values to report FT4222H specific status.
3.1 Typedefs
The following typedefs have been defined for keeping cross platform portability:
typedef
typedef
typedef
typedef
typedef
typedef
typedef
typedef
unsigned long DWORD
unsigned char uint8
unsigned short uint16
unsigned long uint32
signed char int8
signed short int16
signed long int32
unsigned char bool
Please refer to Appendix A for more enumeration and structure definitions.
3.2 FT4222 General Functions
The functions listed in this section are system-wise configuration functions.
3.2.1 Open and Close
An application of LibFT4222 should open the device and get a handle for subsequent
accesses by calling FT_Open or FT_OpenEx. Both are D2XX API. Please refer to the D2XX
Programmers Guide for more details. In addition, please note that the FT4222H assigns
different functions to different interfaces. For example, under mode 0, interface A is
assigned as SPI or I2C interface, and interface B is assigned as GPIO interface.
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After finishing using the device, FT_Close should be called to release the device.
3.2.2 Un-initialize
FT4222_STATUS FT4222_UnInitialize(FT_HANDLE ftHandle)
Summary:
Release allocated resources. FT4222_Uninitialize should be called before calling FT_Close.
Parameters:
ftHandle
Handle of the device.
Return Value:
FT4222_OK if successful, otherwise the return value is an FT error code.
3.2.3 Set Clock
FT4222_STATUS FT4222_SetClock(FT_HANDLE ftHandle, FT4222_ClockRate clk)
Summary:
Set the system clock rate. The FT4222H supports 4 clock rates: 80MHz, 60MHz, 48MHz,
or 24MHz. By default, the FT4222H runs at 60MHz clock rate.
Parameters:
ftHandle
Handle of the device.
clk
FT4222 system clock rate:
SYS_CLK_60
SYS_CLK_24
SYS_CLK_48
SYS_CLK_80
Return Value:
FT4222_OK if successful, otherwise the return value is an FT error code.
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3.2.4 Get Clock
FT4222_STATUS FT4222_GetClock(FT_HANDLE ftHandle, FT4222_ClockRate* pClk)
Summary:
Get the current system clock rate.
Parameters:
ftHandle
Handle of the device.
pClk
Pointer to a variable of type FT4222_ClockRate where the value will be
stored.
Return Value:
FT4222_OK if successful, otherwise the return value is an FT error code.
3.2.5 Set Suspend Out
FT4222_STATUS FT4222_SetSuspendOut(FT_HANDLE ftHandle, BOOL enable)
Summary:
Enable or disable, suspend out, which will emit a signal when FT4222H enters suspend
mode. Please note that the suspend-out pin is not available under mode 2.
Parameters:
ftHandle
Handle of the device.
enable
TRUE to enable suspend out and configure GPIO2 as an output pin for
emitting a signal when suspended.
FALSE to switch back to GPIO2.
Return Value:
FT4222_OK if successful, otherwise the return value is an FT error code.
3.2.6 Set Wake Up/Interrupt
FT4222_STATUS FT4222_SetWakeUpInterrupt(FT_HANDLE ftHandle, BOOL enable)
Summary:
Enable or disable wakeup/interrupt.
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Parameters:
ftHandle
Handle of the device.
enable
TRUE to configure GPIO3 as an input pin for wakeup/interrupt.
FALSE to switch back to GPIO3.
Return Value:
FT4222_OK if successful, otherwise the return value is an FT error code.
3.2.7 Set Interrupt Trigger Condition
FT4222_STATUS FT4222_SetInterruptTrigger(FT_HANDLE ftHandle, GPIO_Trigger
trigger)
Summary:
Set trigger condition for the pin wakeup/interrupt
Parameters:
ftHandle
Handle of the device.
trigger
Trigger condition. One of the following:
GPIO_TRIGGER_RISING
GPIO_TRIGGER_FALLING
GPIO_TRIGGER_LEVEL_HIGH
GPIO_TRIGGER_LEVEL_LOW
Return Value:
FT4222_OK if successful, otherwise the return value is an FT error code.
3.2.8
Get Max Transfer Size
FT4222_STATUS
pMaxSize)
FT4222_GetMaxTransferSize(FT_HANDLE
ftHandle,
uint16*
Summary:
This function returns the maximum packet size in a transaction. It will be affected by
different bus speeds, chip modes, and functions.
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Parameters:
ftHandle
Handle of the device.
pMaxSize
Pointer to a variable of type unit16 where the returning value will be
stored.
Return Value:
FT4222_OK if successful, otherwise the return value is an FT error code.
3.2.9
Set Event Notification
FT4222_STATUS
FT4222_SetEventNotification(FT_HANDLE
dwEventMask, PVOID pvArg)
ftHandle,
DWORD
Summary:
Sets conditions for event notification.
An application can use this function to set up conditions which allow a thread to block
until one of the conditions is met. Typically, an application will create an event, call this
function, and then block on the event. When the conditions are met, the event is set,
and the application thread unblocked. Usually, the event is set to notify the application
to check the condition. The application needs to check the condition again before it goes
to handle the condition.
Parameters:
ftHandle
Handle of the device.
dwEventMask
Conditions that cause the event to be set. It is a bit-map that describes
the events the application is interested in. Currently, this function only
supports the event below:
pvArg
FT4222_EVENT_RXCHAR
The event will be set when a data packet has been received by
the device.
Interpreted as the handle of an event which has been created by the
application. If one of the event conditions is met, the event is set.
Return Value:
FT4222_OK if successful, otherwise the return value is an FT error code.
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3.2.10 Get Version
FT4222_STATUS FT4222_GetVersion(FT_HANDLE ftHandle, FT4222_Version* pVersion)
Summary:
Get the versions of FT4222H and LibFT4222.
Parameters:
ftHandle
Handle of the device.
pVersion
Pointer to a variable of type FT4222_Version where the value will be
stored. Type FT4222_Version is defined as follows:
struct FT4222_Version
{
DWORD chipVersion; // The version of FT4222H chip
DWORD dllVersion;
// The version of LibFT4222
};
Revision A chips report chipVersion as 0x42220100; revision B chips
report 0x42220200. Revision B chips require version 1.2 or later of
LibFT4222, indicated by dllVersion being greater than 0x01020000.
Return Value:
FT4222_OK if successful, otherwise the return value is an FT error code.
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3.3 SPI Master Functions
The FT4222H can be initialized as an SPI master under all modes.
As SPI master, it allows data transfers in three types of bit width:
Single SPI transfer – Standard data transfer format – data is read and written
simultaneously
DUAL SPI Transfer/Receive - Data is transferred out or received in on 2 SPI lines
simultaneously
QUAD SPI Transfer/Receive – Data is transferred out or received in on 4 SPI lines
simultaneously
Please refer to DS_FT4222H for more details.
3.3.1 SPI Master Init
FT4222_STATUS FT4222_SPIMaster_Init(FT_HANDLE ftHandle,
FT4222_SPIMode ioLine, FT4222_SPIClock clock_div,
FT4222_SPICPOL cpol, FT4222_SPICPHA cpha, uint8 ssoMap)
Summary:
Initialize the FT4222H as an SPI master.
In order to support various types of SPI slave devices, the FT4222H SPI master is
configurable using the following parameters:
IO lines: SPI transmission lines. The FT4222H SPI supports single, dual, or quad
transmission mode. An application may override this initial selection dynamically
using FT4222_SPIMaster_SetLines. For example, commands might be sent in
single mode but data transferred in dual or quad mode.
Clock divider: SPI clock rate is subject to system clock. The FT4222H SPI clock
could be 1/2, 1/4, 1/8, 1/16, 1/32, 1/64, 1/128, 1/256, or 1/512 system clock
rate.
Clock polarity: Active high or active low.
Clock phase: Data is sampled on the leading (first) or trailing (second) clock edge.
Slave selection output pins: Select slave devices by ss0o, ss1o, ss2o, ss3o. The
FT4222H supports active low only.
Please note that the FT4222H has only one SPI controller. Even though the FT4222H
provides up to 4 interfaces for connecting up to 4 SPI slave devices as the Figure 1.4,
the 4 slave devices share the same SPI data bus: MOSI, MISO, and SCK. A user can
decide how to map the 4 interfaces to the 4 SS signals (ss0o, ss1o, ss2o and ss3o) by
the ssoMap parameter. For example:
a. interface 0 for ss0o and ss1o
b. interface 1 for ss2o
c. interface 2 for ss3o
d. interface 3 is not used
The 4 interfaces cannot work simultaneously because there is only one data bus.
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Parameters:
ftHandle
Handle of the device.
ioLine
SPI transmission lines:
clock_div
cpol
cpha
ssoMap
SPI_IO_SINGLE
SPI_IO_DUAL
SPI_IO_QUAD
Clock divider:
CLK_DIV_2
(1/2
System Clock)
CLK_DIV_4
(1/4
System Clock)
CLK_DIV_8
(1/8
System Clock)
CLK_DIV_16 (1/16 System Clock)
CLK_DIV_32 (1/32 System Clock)
CLK_DIV_64 (1/64 System Clock)
CLK_DIV_128 (1/128 System Clock)
CLK_DIV_256 (1/256 System Clock)
CLK_DIV_512 (1/512 System Clock)
Clock polarity:
CLK_IDLE_LOW
CLK_IDLE_HIGH
Clock phase:
CLK_LEADING
CLK_TRAILING
Slave selection output pins. It’s a bitmap:
Bit 0: select device connected with ss0o
Bit 1: select device connected with ss1o
Bit 2: select device connected with ss2o
Bit 3: select device connected with ss3o
Return Value:
FT4222_OK if successful, otherwise the return value is an FT error code.
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3.3.2 SPI Master Set Lines
FT4222_STATUS FT4222_SPIMaster_SetLines(FT_HANDLE ftHandle,
FT4222_SPIMode spiMode)
Summary:
Switch the FT4222H SPI master to single, dual, or quad mode. This overrides the mode
passed to FT4222_SPIMaster_init. This might be needed if a device accepts commands
in single mode but data transfer is to use dual or quad mode.
Parameters:
ftHandle
Handle of the device.
spiMode
SPI mode could be:
SPI_IO_SINGLE
SPI_IO_DUAL
SPI_IO_QUAD
Return Value:
FT4222_OK if successful, otherwise the return value is an FT error code.
3.3.3 SPI Master Single Read
FT4222_STATUS FT4222_SPIMaster_SingleRead(FT_HANDLE ftHandle, uint8* buffer,
uint16 bytesToRead, uint16* sizeOfRead, BOOL isEndTransaction)
Summary:
Under SPI single mode, read data from an SPI slave.
Parameters:
ftHandle
Handle of the device.
Buffer
Pointer to the buffer that receives the data from the device.
bytesToRead
Number of bytes to read from the device.
sizeOfRead
Pointer to a variable of type uint16 which receives the number of
bytes read from the device.
isEndTransaction
If TRUE the Slave Select pin will be raised at the end of the read.
Return Value:
FT4222_OK if successful, otherwise the return value is an FT error code.
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3.3.4 SPI Master Single Write
FT4222_STATUS FT4222_SPIMaster_SingleWrite(FT_HANDLE ftHandle, uint8* buffer,
uint16 bytesToWrite, uint16* sizeTransferred, BOOL isEndTransaction)
Summary:
Under SPI single mode, write data to an SPI slave.
Parameters:
ftHandle
Handle of the device.
Buffer
Pointer to the buffer that contains the data to be written to the
device.
bytesToWrite
Number of bytes to write to the device.
sizeTransferred
Pointer to a variable of type uint16 which receives the number of
bytes written to the device.
isEndTransaction
If TRUE the Slave Select pin will be raised at the end of the write.
Return Value:
FT4222_OK if successful, otherwise the return value is an FT error code.
3.3.5 SPI Master Single Read and Write
FT4222_STATUS FT4222_SPIMaster_SingleReadWrite(FT_HANDLE ftHandle, uint8*
readBuffer, uint8* writeBuffer, uint16 sizeToTransfer, uint16* sizeTransferred, BOOL
isEndTransaction)
Summary:
Under SPI single mode, full-duplex write data to and read data from an SPI slave.
The standard SPI protocol simultaneously sends data onto the MOSI data line and
receives data from the MISO line as shown below.
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Figure 3.1 SPI full duplex communication
Parameters:
ftHandle
Handle of the device.
readBuffer
Pointer to the buffer that receives data from the device.
writeBuffer
Pointer to the buffer that contains data to be written to the device.
sizeToTransfer
The size of read and write buffer. They must be the same.
sizeTransferred
Pointer to a variable of type uint16 which receives the number of
bytes read and written to the device.
isEndTransaction
TRUE to raise the pin of SS at the end of the transaction.
Return Value:
FT4222_OK if successful, otherwise the return value is an FT error code.
3.3.6 SPI Master Multi Read and Write
FT4222_STATUS FT4222_SPIMaster_MultiReadWrite(FT_HANDLE ftHandle, uint8*
readBuffer, uint8* writeBuffer, uint8 singleWriteBytes,uint16 multiWriteBytes,uint16
multiReadBytes, uint32* sizeOfRead)
Summary:
Under SPI dual or quad mode, write data to and read data from an SPI slave.
The figure below illustrates the dual-SPI protocol supported by the FT4222H SPI master.
It is a mixed protocol initiated with a single write transmission, which may be an SPI
command and dummy cycles, and followed by dual-write and dual-read transmission
that use 2 signals in parallel for the data. All three parts of the protocol are optional. For
example, developers can ignore the multi-read part by setting multiReadBytes=0.
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Figure 3.2 Dual SPI communication
The figure below illustrates the quad-SPI protocol supported by the FT4222H SPI master.
It is the same as the dual-protocol illustrated above - it is a mixed protocol initiated with
a single write transmission and followed by quad-write and quad-read transmission that
use 4 signals in parallel for the data.
Figure 3.3 Quad SPI communication
Parameters:
ftHandle
Handle of the device.
readBuffer
Pointer to the buffer that receives the data from the device.
writeBuffer
Pointer to the buffer that contains the data to be written to the
device. The data is comprised of both single-write and multi-write
parts. It starts with single-write data, whose length is specified by
singleWriteBytes, and followed by multi-write data, whose length is
specified by multiWriteBytes.
singleWriteBytes
Number of bytes in writeBuffer will be written on single-line.
multiWriteBytes
Number of bytes in writeBuffer will be written on multi-line.
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multiReadBytes
Number of bytes to read on multi-line.
sizeOfRead
Pointer to a variable of type uint16 which receives the number of
bytes read from the device.
Return Value:
FT4222_OK if successful, otherwise the return value is an FT error code.
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3.4 SPI Slave Functions
The FT4222H can be initialized as an SPI slave under mode 0 to mode 3. As an SPI slave,
the FT4222H only supports the standard single SPI transfer. Refer to DS_FT4222H for
more details.
A USB-SPI bridge usually faces the challenge that USB cannot guarantee the throughput
for each endpoint, but SPI requires data transmission at a steady rate. It is highly
possible when an SPI master starts to request data from a USB-SPI slave bridge device,
the data has not arrived from the USB host side yet. In addition, SPI does not have a
standard protocol to allow the master side to check the status of the slave side. The
protocol is usually provided by an SPI slave device on its own, which makes the SPI
master device communicate with the slave device by its specified commands.
The FT4222H and LibFT4222 design have implemented an SPI slave protocol which must
be used to handle the integrity of data transmission.
In this protocol, a master starts an SPI transaction by sending a packet in the format
illustrated below:
Figure 3.4 SPI Slave Protocol Format
It starts with Sync word: 0x5A, and followed by a Command field:
Command
Value
Master Transfer
0x80
Slave Transfer
0x81
Short master transfer (without checksum)
0x82
Short slave transfer (without checksum)
0x83
ACK
0x84
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SN stands for serial number. It is monotonically increased, and helps to identify packets.
Size is a two-byte field, which is the size of the data field in big-endian order. The
Checksum is the summation of all data fields’ lower two bytes starting from the first
byte, the sync word, to the latest data byte.
The checksum is in big-endian order as well. When the slave, FT4222H, receives the
transfer request from the master, it will respond with an ACK. The master can confirm
the transaction succeeded when it receives the ACK from the slave.
Figure 3.5 SPI Master transfer request
Here is an example of an ACK packet. The SN field of the ACK packet identifies which
request it corresponds to. An ACK packet has no data therefore the Size field should be 0.
Figure 3.6 An example of the SPI slave responding with ACK
If the SPI master does not receive the ACK response from the slave, it should send its
request again.
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Figure 3.7 An example of when the SPI master doesn’t receive ACK
When the FT4222H SPI slave wants to send data to the master, which may be requested
by the master, it just sends a transfer request in the same protocol format as shown in
figure 3.4.
Figure 3.8 Slave sends transfer request
3.4.1 SPI Slave Init
FT4222_STATUS FT4222_SPISlave_Init(FT_HANDLE ftHandle)
Summary:
Initialize the FT4222H as an SPI slave.
Parameters:
ftHandle
Handle of the device.
Return Value:
FT4222_OK if successful, otherwise the return value is an FT error code.
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3.4.2 SPI Slave Get Rx Status
FT4222_STATUS
pRxSize)
FT4222_SPISlave_GetRxStatus(FT_HANDLE
ftHandle,
uint16*
Summary:
Get number of bytes in the receive queue.
Parameters:
ftHandle
Handle of the device.
pRxSize
Pointer to a variable of type uint16 which receives the number of bytes in
the receive queue.
Return Value:
FT4222_OK if successful, otherwise the return value is an FT error code.
3.4.3 SPI Slave Read
FT4222_STATUS FT4222_SPISlave_Read(FT_HANDLE ftHandle, uint8* buffer, uint16
bytesToRead, uint16* sizeOfRead)
Summary:
Read data from the receive queue of the SPI slave device.
Parameters:
ftHandle
Handle of the device.
buffer
Pointer to the buffer that receives the data from the device.
bytesToRead
Number of bytes to read from the device.
sizeOfRead
Pointer to a variable of type uint16 which receives the number of bytes
read from the device.
Return Value:
FT4222_OK if successful, otherwise the return value is an FT error code.
3.4.4 SPI Slave Write
FT4222_STATUS FT4222_SPISlave_Write(FT_HANDLE ftHandle, uint8* buffer, uint16
bytesToWrite, uint16* sizeTransferred)
Summary:
Write data to the transmit queue of the SPI slave device.
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Parameters:
ftHandle
Handle of the device.
buffer
Pointer to the buffer that contains the data to be written to the device.
bytesToWrite
Number of bytes to write to the device.
sizeTransferred
Pointer to a variable of type uint16 which receives the number of
bytes written to the device.
Return Value:
FT4222_OK if successful, otherwise the return value is an FT error code.
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3.5 SPI General Functions
3.5.1
SPI Reset Transaction
FT4222_STATUS FT4222_SPI_ResetTransaction(FT_HANDLE ftHandle, uint8 spiIdx)
Summary:
Reset the SPI transaction.
Parameters:
ftHandle
Handle of the device.
spiIdx
The index of the SPI transaction, which ranges from 0~3 depending on
the mode of the chip. For example, under mode 0 and mode 3 as we
mentioned in chapter 1.1, it should be 0 because there is only one SPI
master or slave connection, and so forth.
Return Value:
FT4222_OK if successful, otherwise the return value is an FT error code.
3.5.2
SPI Reset
FT4222_STATUS FT4222_SPI_Reset (FT_HANDLE ftHandle)
Summary:
Reset the SPI master or slave device.
Parameters:
ftHandle
Handle of the device.
Return Value:
FT4222_OK if successful, otherwise the return value is an FT error code.
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3.5.3 SPI Set Driving Strength
FT4222_STATUS FT4222_SPI_SetDrivingStrength(FT_HANDLE ftHandle,
SPI_DrivingStrength clkStrength,
SPI_DrivingStrength ioStrength,
SPI_DrivingStrength ssoStrength)
Summary:
For the FT4222H SPI, set the driving strength of clk, io, and sso pins.
Parameters:
ftHandle
Handle of the device.
clkStrength
The driving strength of the clk pin (SPI master only):
ioStrength
ssoStrength
DS_4MA
DS_8MA
DS_12MA
DS_16MA
The driving strength of the io pin:
DS_4MA
DS_8MA
DS_12MA
DS_16MA
The driving strength of the sso pin (SPI master only):
DS_4MA
DS_8MA
DS_12MA
DS_16MA
Return Value:
FT4222_OK if successful, otherwise the return value is an FT error code.
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3.6 I2C Master Functions
I2C (Inter Integrated Circuit) is a multi-master serial bus invented by Philips. I2C uses
two bi-directional open-drain wires called serial data (SDA) and serial clock (SCL).
Common I²C bus speeds are the 100 kbit/s standard mode (SM), 400 kbit/s fast mode
(FM), 1 Mbit/s Fast mode plus (FM+), and 3.4 Mbit/s High Speed mode (HS)
The FT4222H device can be initialized as either an I2C master or I2C slave under mode 0
and mode 3. Here is a brief overview of FT4222H I2C features:
Fully compatible to I2C v2.1 and v3 specification
7-bit address support
Support 4 speed configurations: 100KHz(SM), 400KHz(FM), 1MHz(FM+), and
3.4MHz(HS).
Clock stretching support in both master and slave mode.
Refer to DS_FT4222H for more details.
3.6.1 I2C Master Init
FT4222_STATUS FT4222_I2CMaster_Init(FT_HANDLE ftHandle, uint32 kbps)
Summary:
Initialize the FT4222H as an I2C master with the requested I2C speed.
Parameters:
ftHandle
Handle of the device.
kbps
The speed of I2C transmission. It ranges from 60K bps to 3400K bps. By
specified speed, the initialization function helps to setup the bus speed
with the corresponding mode. This parameter is used to configure the
FT4222H to be either SM, FB, FM+ or HS mode.
Return Value:
FT4222_OK if successful, otherwise the return value is an FT error code.
3.6.2 I2C Master Read
FT4222_STATUS FT4222_I2CMaster_Read(FT_HANDLE ftHandle, uint16 slaveAddress,
uint8* buffer, uint16 bytesToRead, uint16* sizeTransferred)
Summary:
Read data from the specified I2C slave device with START and STOP conditions.
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Parameters:
ftHandle
Handle of the device.
slaveAddress
Address of the target I2C slave.
buffer
Pointer to the buffer that receives data from the device.
bytesToRead
Number of bytes to read from the device.
sizeTransferred
Pointer to a variable of type uint16 which receives the number of
bytes read from the device.
Return Value:
FT4222_OK if successful, otherwise the return value is an FT error code.
3.6.3 I2C Master Write
FT4222_STATUS FT4222_I2CMaster_Write(FT_HANDLE ftHandle, uint16 slaveAddress,
uint8* buffer, uint16 bytesToWrite, uint16* sizeTransferred)
Summary:
Write data to the specified I2C slave device with START and STOP conditions.
Parameters:
ftHandle
Handle of the device.
slaveAddress
Address of the target I2C slave.
buffer
Pointer to the buffer that contains the data to be written to the device.
bytesToWrite
Number of bytes to write to the device.
sizeTransferred
Pointer to a variable of type uint16 which receives the number of
bytes written to the device.
Return Value:
FT4222_OK if successful, otherwise the return value is an FT error code.
3.6.4 I2C Master Write Extension
FT4222_STATUS FT4222_I2CMaster_WriteEx(FT_HANDLE ftHandle, uint16
deviceAddress, uint8 flag, uint8* buffer, uint16 bytesToWrite, uint16* sizeTransferred)
Summary:
Write data to the specified I2C slave device with the specified I2C condition.
This function is supported by the rev B FT4222H or later.
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Parameters:
ftHandle
Handle of the device.
slaveAddress
Address of the target I2C slave.
flag
The I2C condition will be sent with this I2C transaction
START = 0x02
Repeated_START = 0x03
Repeated_START will not send master code in HS mode
STOP = 0x04
START_AND_STOP = 0x06
buffer
Pointer to the buffer that contains the data to be written to the device.
bytesToWrite
Number of bytes to write to the device.
sizeTransferred
Pointer to a variable of type uint16 which receives the number of
bytes written to the device.
Return Value:
FT4222_OK if successful, otherwise the return value is an FT error code.
3.6.5 I2C Master Read Extension
FT4222_STATUS
FT4222_I2CMaster_ReadEx(FT_HANDLE
ftHandle,
uint16
deviceAddress, uint8 flag, uint8* buffer, uint16 bytesToRead, uint16* sizeTransferred)
Summary:
Read data from the specified I2C slave device with the specified I2C condition.
This function is supported by the rev B FT4222H or later.
Parameters:
ftHandle
Handle of the device.
slaveAddress
Address of the target I2C slave.
flag
The I2C condition will be sent with this I2C transaction
START = 0x02
Repeated_START = 0x03
Repeated_START will not send master code in HS mode
STOP = 0x04
START_AND_STOP = 0x06
buffer
Pointer to the buffer that receives the data from the device.
bytesToRead
Number of bytes to read from the device.
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Pointer to a variable of type uint16 which receives the number of
bytes read from the device.
Return Value:
FT4222_OK if successful, otherwise the return value is an FT error code.
I²C combined message support
In a combined message, each read or write begins with a START and the slave address.
After the first START, the subsequent starts are referred to as repeated START bits;
repeated START bits are not preceded by STOP bits, which indicate to the slave the next
transfer is part of the same message.
SR = repeated START condition
Here is an example for typical usage of I2C combined message:
// Write to I2C slave with START bit
FT4222_I2CMaster_WriteEx(ftHandle,
sizeTransferred);
deviceAddress,
START,
buffer,
bufferSize,
// Read from I2C slave with Repeated START and STOP bit
// Use Repeated_START flag instead of START to avoid the FT4222H sending master
code
// again in HS mode
FT4222_I2CMaster_ReadEx(ftHandle, deviceAddress, Repeated_START | STOP, buffer,
bufferSize, sizeTransferred);
3.6.6 I2C Master GetStatus
FT4222_STATUS
*controllerStatus)
FT4222_I2CMaster_GetStatus(FT_HANDLE
ftHandle,
uint8
Summary:
Read the status of the I2C master controller. This can be used to poll a slave until its
write-cycle is complete.
Parameters:
ftHandle
Handle of the device.
controllerStatus
Address of byte to receive status flags:
bit 0: controller busy: all other status bits invalid
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ACK
8 bit data
STOP
8 bit data
ACK
ACK
7 bit slave
address
read
SR
8 bit data
ACK
ACK
write
Start
7 bit slave
address
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bit 1: error condition
bit 2: slave address was not acknowledged during last operation
bit 3: data not acknowledged during last operation
bit 4: arbitration lost during last operation
bit 5: controller idle
bit 6: bus busy
The
header
file
provides
convenience
I2CM_BUS_BUSY) to test these bits.
macros
(such
as
Return Value:
FT4222_OK if successful, otherwise the return value is an FT error code.
3.6.7 I2C Master Reset
FT4222_STATUS FT4222_I2CMaster_Reset(FT_HANDLE ftHandle)
Summary:
Reset the I2C master device.
If the I2C bus encounters errors or works abnormally, this function will reset the I2C
device. It is not necessary to call I2CMaster_Init again after calling this reset function.
Parameters:
ftHandle
Handle of the device.
Return Value:
FT4222_OK if successful, otherwise the return value is an FT error code.
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3.7 I2C Slave Functions
The FT4222H device can be initialized as an I2C slave under mode 0 and mode 3. It
conforms to v2.1 and v3.0 of the I2C specification and supports all the transmission
modes: Standard, Fast, Fast-plus and High Speed.
When the I2C slave receives data from the I2C bus, it will keep the data in its internal
receive buffer (256 bytes), and then send the data to the USB host through IN packets.
When data is requested by an I2C master, data will be moved from an OUT packet to the
transmit register directly.
3.7.1 I2C Slave Init
FT4222_STATUS FT4222_I2CSlave_Init(FT_HANDLE ftHandle)
Summary:
Initialize FT4222H as an I2C slave.
Parameters:
ftHandle
Handle of the device.
Return Value:
FT4222_OK if successful, otherwise the return value is an FT error code.
3.7.2 I2C Slave Get Address
FT4222_STATUS FT4222_I2CSlave_GetAddress(FT_HANDLE ftHandle, uint8* pAddr)
Summary:
Get the address of the I2C slave device.
Parameters:
ftHandle
Handle of the device.
pAddr
Pointer to a variable of type uint16 which receives the address of the I2C
slave device.
Return Value:
FT4222_OK if successful, otherwise the return value is an FT error code.
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3.7.3 I2C Slave Set Address
FT4222_STATUS FT4222_I2CSlave_SetAddress(FT_HANDLE ftHandle, uint8 addr)
Summary:
Set the address of the I2C slave device.
Parameters:
ftHandle
Handle of the device.
addr
The 7-bit address of the I2C slave device.
Return Value:
FT4222_OK if successful, otherwise the return value is an FT error code.
3.7.4
I2C Slave Get Rx Status
FT4222_STATUS
pRxSize)
FT4222_I2CSlave_GetRxStatus(FT_HANDLE
ftHandle,
uint16*
Summary:
Get number of bytes in the receive queue.
Parameters:
ftHandle
Handle of the device.
pRxSize
Pointer to a variable of type uint16 which receives the number of bytes in
the receive queue.
Return Value:
FT4222_OK if successful, otherwise the return value is an FT error code.
3.7.5
I2C Slave Read
FT4222_STATUS FT4222_I2CSlave_Read(FT_HANDLE ftHandle, uint8* buffer, uint16
bytesToRead, uint16* sizeTransferred)
Summary:
Read data from the buffer of the I2C slave device.
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Parameters:
ftHandle
Handle of the device.
buffer
Pointer to the buffer that receives the data from the device.
bytesToRead
Number of bytes to read from the device.
sizeTransferred
Pointer to a variable of type uint16 which receives the number of
bytes read from the device.
Return Value:
FT4222_OK if successful, otherwise the return value is an FT error code.
3.7.6
I2C Slave Write
FT4222_STATUS FT4222_I2CSlave_Write(FT_HANDLE ftHandle, uint8* buffer, uint16
bytesToWrite, uint16* sizeTransferred)
Summary:
Write data to the buffer of I2C slave device.
Parameters:
ftHandle
Handle of the device.
buffer
Pointer to the buffer that contains the data to be written to the device.
bytesToWrite
Number of bytes to write to the device.
sizeTransferred
Pointer to a variable of type uint16 which receives the number of
bytes written to the device.
Return Value:
FT4222_OK if successful, otherwise the return value is an FT error code.
3.7.7
I2C Slave Reset
FT4222_STATUS FT4222_I2CSlave_Reset(FT_HANDLE ftHandle)
Summary:
Reset the I2C slave device.
Parameters:
ftHandle
Handle of the device.
Return Value:
FT4222_OK if successful, otherwise the return value is an FT error code.
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3.8 GPIO Functions
The FT4222H contains 4 GPIO. When the USB GPIO interface is supported, chip mode 0
and mode 1, LibFT4222 helps application developers to control GPIO directly. However,
each GPIO pin is multiplexed with interrupt/suspend out/SPI slave select/I2C functions
as listed below:
gpio0 / ss1o / scl
gpio1 / ss2o / sda
gpio2 / ss3o / suspend out
gpio3 / wakeup/intr
The number of GPIO pins available depends on the mode of the chip. For example, if the
FT4222H is initialized as an I2C device, as shown above, the pins of gpio0 and gpio1 will
be switched to scl and sda, and cannot be used as GPIO. If suspend out and remote
wakeup are enabled gpio2 and gpio3 cannot be used as GPIO.
The FT4222H supports GPIO on the second USB interface in mode 0 or on the fourth
interface in mode 2 (Please refer table 2.1 for chip mode and interface).
3.8.1 GPIO Init
FT4222_STATUS FT4222_GPIO_Init(FT_HANDLE ftHandle, GPIO_Dir gpioDir[4])
Summary:
Initialize the GPIO interface of the FT4222H.
Please note the GPIO interface is available on the 2nd USB interface in mode 0 or on the
4th USB interface in mode 1.
Parameters:
ftHandle
Handle of the device.
gpioDir
An array defines the directions of 4 GPIO pins. The GPIO direction will be:
GPIO_OUTPUT
GPIO_INPUT
Return Value:
FT4222_OK if successful, otherwise the return value is an FT error code.
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3.8.2 GPIO Read
FT4222_STATUS
BOOL* pValue)
FT4222_GPIO_Read(FT_HANDLE
ftHandle,
GPIO_Port
portNum,
Summary:
Read the value from the specified GPIO pin.
Parameters:
ftHandle
Handle of the device.
portNum
One of the following GPIO ports:
pValue
GPIO_PORT0
GPIO_PORT1
GPIO_PORT2
GPIO_PORT3
Pointer to a variable of type BOOL which receives the value of the GPIO
pin.
Return Value:
FT4222_OK if successful, otherwise the return value is an FT error code.
3.8.3 GPIO Write
FT4222_STATUS
BOOL bValue)
FT4222_GPIO_Write(FT_HANDLE
ftHandle,
GPIO_Port
portNum,
Summary:
Write value to the specified GPIO pin.
Parameters:
ftHandle
Handle of the device.
portNum
One of the following GPIO port:
bValue
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GPIO_PORT1
GPIO_PORT2
GPIO_PORT3
The output value.
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Return Value:
FT4222_OK if successful, otherwise the return value is an FT error code.
3.8.4 GPIO Set Input Trigger
FT4222_STATUS FT4222_GPIO_SetInputTrigger(FT_HANDLE ftHandle, GPIO_Port
portNum, GPIO_Trigger trigger)
Summary:
Set software trigger conditions on the specified GPIO pin.
This function allows developers to monitor value changes of the GPIO pins. Values that
satisfy the trigger condition will be stored in a queue. For example, if
GPIO_TRIGGER_RISING is set on GPIO0, and GPIO0 then changes value from 0 to 1, the
event GPIO_TRIGGER_RISING will be recorded into the queue. Developers can query the
queue status by FT4222_GPIO_GetTriggerStatus, and FT4222_GPIO_ReadTriggerQueue.
Parameters:
ftHandle
Handle of the device.
portNum
One of the following GPIO port:
trigger
GPIO_PORT0
GPIO_PORT1
GPIO_PORT2
GPIO_PORT3
Combination of the following trigger conditions:
GPIO_TRIGGER_RISING
GPIO_TRIGGER_FALLING
GPIO_TRIGGER_LEVEL_HIGH
GPIO_TRIGGER_LEVEL_LOW
Return Value:
FT4222_OK if successful, otherwise the return value is an FT error code.
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3.8.5 GPIO Get Trigger Status
FT4222_STATUS FT4222_GPIO_GetTriggerStatus(FT_HANDLE ftHandle, GPIO_Port
portNum, uint16* pQueueSize)
Summary:
Get the size of trigger event queue.
Parameters:
ftHandle
Handle of the device.
portNum
One of the following GPIO port:
pQueueSize
GPIO_PORT0
GPIO_PORT1
GPIO_PORT2
GPIO_PORT3
Pointer to a variable of type unit16 where the returning value will be
stored.
Return Value:
FT4222_OK if successful, otherwise the return value is an FT error code.
3.8.6 GPIO Read Trigger Queue
FT4222_STATUS FT4222_GPIO_ReadTriggerQueue(FT_HANDLE ftHandle, GPIO_Port
portNum, GPIO_Trigger* events, uint16 readSize, uint16* sizeofRead)
Summary:
Get events recorded in the trigger event queue. Trigger conditions are set by a call to
FT4222_GPIO_SetInputTrigger. After calling this function, all events will be removed
from the event queue.
Parameters:
ftHandle
Handle of the device.
portNum
One of the following GPIO port:
events
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GPIO_PORT0
GPIO_PORT1
GPIO_PORT2
GPIO_PORT3
Pointer to the buffer that receives the values of the trigger event queue.
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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.
Return Value:
FT4222_OK if successful, otherwise the return value is an FT error code.
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4 Contact Information
Head Office – Glasgow, UK
Branch Office – Tigard, Oregon, USA
Future Technology Devices International Limited
Unit 1, 2 Seaward Place, Centurion Business Park
Glasgow G41 1HH
United Kingdom
Tel: +44 (0) 141 429 2777
Fax: +44 (0) 141 429 2758
Future Technology Devices International Limited
(USA)
7130 SW Fir Loop
Tigard, OR 97223-8160
USA
Tel: +1 (503) 547 0988
Fax: +1 (503) 547 0987
E-mail (Sales)
E-mail (Support)
E-mail (General Enquiries)
[email protected]
[email protected]
[email protected]
E-Mail (Sales)
E-Mail (Support)
E-Mail (General Enquiries)
Branch Office – Taipei, Taiwan
Branch Office – Shanghai, China
Future Technology Devices International Limited
(Taiwan)
2F, No. 516, Sec. 1, NeiHu Road
Taipei 114
Taiwan , R.O.C.
Tel: +886 (0) 2 8791 3570
Fax: +886 (0) 2 8791 3576
E-mail (Sales)
E-mail (Support)
E-mail (General Enquiries)
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
Future Technology Devices International Limited
(China)
Room 1103, 666 West Huaihai Road,
Shanghai, 200052
China
Tel: +86 21 62351596
Fax: +86 21 62351595
E-mail (Sales)
E-mail (Support)
E-mail (General Enquiries)
[email protected]
[email protected]
[email protected]
Web Site
http://ftdichip.com
Distributor and Sales Representatives
Please visit the Sales Network page of the FTDI Web site for the contact details of our distributor(s) and sales
representative(s) in your country.
System and equipment manufacturers and designers are responsible to ensure that their systems, and any Future Technology
Devices International Ltd (FTDI) devices incorporated in their systems, meet all applicable safety, regulatory and system-level
performance requirements. All application-related information in this document (including application descriptions, suggested
FTDI devices and other materials) is provided for reference only. While FTDI has taken care to assure it is accurate, this
information is subject to customer confirmation, and FTDI disclaims all liability for system designs and for any applications
assistance provided by FTDI. Use of FTDI devices in life support and/or safety applications is entirely at the user’s risk, and the
user agrees to defend, indemnify and hold harmless FTDI from any and all damages, claims, suits or expense resulting from
such use. This document is subject to change without notice. No freedom to use patents or other intellectual property rights is
implied by the publication of this document. Neither the whole nor any part of the information contained in, or the product
described in this document, may be adapted or reproduced in any material or electronic form without the prior written consent
of the copyright holder. Future Technology Devices International Ltd, Unit 1, 2 Seaward Place, Centurion Business Park,
Glasgow G41 1HH, United Kingdom. Scotland Registered Company Number: SC136640
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Appendix A – Enumeration and Structure Definitions
Enumeration
FT4222_STATUS
FT4222_DEVICE_NOT_SUPPORTED
= 1000
FT4222_CLK_NOT_SUPPORTED // spi master do not support 80MHz/CLK_2
FT4222_VENDER_CMD_NOT_SUPPORTED
FT4222_IS_NOT_SPI_MODE
FT4222_IS_NOT_I2C_MODE
FT4222_IS_NOT_SPI_SINGLE_MODE
FT4222_IS_NOT_SPI_MULTI_MODE
FT4222_WRONG_I2C_ADDR
FT4222_INVAILD_FUNCTION
FT4222_INVALID_POINTER
FT4222_EXCEEDED_MAX_TRANSFER_SIZE
FT4222_FAILED_TO_READ_DEVICE
FT4222_I2C_NOT_SUPPORTED_IN_THIS_MODE
FT4222_GPIO_NOT_SUPPORTED_IN_THIS_MODE
FT4222_GPIO_EXCEEDED_MAX_PORTNUM
FT4222_GPIO_WRITE_NOT_SUPPORTED
FT4222_GPIO_PULLUP_INVALID_IN_INPUTMODE
FT4222_GPIO_PULLDOWN_INVALID_IN_INPUTMODE
FT4222_GPIO_OPENDRAIN_INVALID_IN_OUTPUTMODE
FT4222_INTERRUPT_NOT_SUPPORTED
FT4222_GPIO_INPUT_NOT_SUPPORTED
FT4222_EVENT_NOT_SUPPORTED
FT4222_FUN_NOT_SUPPORT
FT4222_ClockRate
SYS_CLK_60 = 0
SYS_CLK_24
SYS_CLK_48
SYS_CLK_80
FT4222_SPIMode
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SPI_IO_NONE
Clearance No.: FTDI#406
= 0
SPI_IO_SINGLE = 1
SPI_IO_DUAL
= 2
SPI_IO_QUAD
= 4
FT4222_SPIClock
CLK_NONE =
0
CLK_DIV_2
// 1/2
System Clock
CLK_DIV_4
// 1/4
System Clock
CLK_DIV_8
// 1/8
System Clock
CLK_DIV_16
// 1/16
System Clock
CLK_DIV_32
// 1/32
System Clock
CLK_DIV_64
// 1/64
System Clock
CLK_DIV_128
// 1/128 System Clock
CLK_DIV_256
// 1/256 System Clock
CLK_DIV_512
// 1/512 System Clock
FT4222_SPICPOL
CLK_IDLE_LOW
=0
CLK_IDLE_HIGH =1
FT4222_SPICPHA
CLK_LEADING
=0
CLK_TRAILING =1
SPI_DrivingStrength
DS_4MA
DS_8MA
DS_12MA
DS_16MA
enum GPIO_Port
GPIO_PORT0
GPIO_PORT1
GPIO_PORT2
GPIO_PORT3
enum GPIO_Dir
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GPIO_OUTPUT
GPIO_INPUT
enum GPIO_Trigger
GPIO_TRIGGER_RISING
GPIO_TRIGGER_FALLING
GPIO_TRIGGER_LEVEL_HIGH
GPIO_TRIGGER_LEVEL_LOW
enum GPIO_Output
GPIO_OUTPUT_LOW
GPIO_OUTPUT_HIGH
enum I2C_MasterFlag
START
= 0x02
Repeated_START = 0x03 // Repeated_START will not send master code in HS mode
STOP
= 0x04
START_AND_STOP = 0x06
// START condition followed by SEND and STOP condition
Structure Definitions
struct FT4222_Version
{
DWORD chipVersion; // The version of FT4222H chip
DWORD dllVersion;
// The version of LibFT4222
};
struct SPI_Slave_Header
{
uint8
syncWord;
uint8
cmd;
uint8
sn;
uint16
size;
};
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Appendix B – References
Document References
DS_FT4222H
D2XX Programmers Guide
D2XX Drivers
Acronyms and Abbreviations
Terms
Description
D2XX
FTDI’s proprietary “direct” driver interface via FTD2XX.DLL
GPIO
General-purpose input/output
I2C
Inter-Integrated Circuit
SPI
Serial Peripheral Interconnect
USB
Universal Serial Bus
USB-IF
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Appendix C – List of Tables & Figures
List of Tables
Table 2.1 Chip mode and device functions ................................................................ 8
List of Figures
Figure 1.1 The software stack ................................................................................. 4
Figure 1.2 Mode 0: FT4222H works as SPI master (quad mode) .................................. 6
Figure 1.3 Mode 0: FT4222H works as I2C master ..................................................... 6
Figure 1.4 Mode 2: FT4222H works as SPI master ..................................................... 7
Figure 3.1 SPI full duplex communication ............................................................... 21
Figure 3.2 Dual SPI communication ....................................................................... 22
Figure 3.3 Quad SPI communication ...................................................................... 22
Figure 3.4 SPI Slave Protocol Format ..................................................................... 24
Figure 3.5 SPI Master transfer request ................................................................... 25
Figure 3.6 An example of the SPI slave responding with ACK .................................... 25
Figure 3.7 An example of when the SPI master doesn’t receive ACK .......................... 26
Figure 3.8 Slave sends transfer request ................................................................. 26
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Appendix D – Revision History
Document Title:
AN_329 User Guide For LibFT4222
Document Reference No.:
FT_000546
Clearance No.:
FTDI#406
Product Page:
http://www.ftdichip.com/FTProducts.htm
Document Feedback:
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Revision
1.0
1.1
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Changes
Date
Initial Release
2014-09-16
Two new I2C functions are added to support
combined message format
Update to FT4222_I2CMaster_WriteEx and
FT4222_I2CMaster_ReadEx
2015-09-10
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