Difference between revisions of "Unit I2C"
Line 409: | Line 409: | ||
! '''Note''' | ! '''Note''' | ||
| To be documented | | To be documented | ||
+ | |- | ||
+ | |} | ||
+ | </div></div> | ||
+ | <br /> | ||
+ | |||
+ | '''RTL I2C functions''' | ||
+ | |||
+ | <div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;"> | ||
+ | <pre style="border: 0; padding-bottom:0px;">function SysI2CAvailable:Boolean;</pre> | ||
+ | <div style="font-size: 14px; padding-left: 12px;">'''Description:''' Check if an I2C device is available</div> | ||
+ | <div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;"> | ||
+ | {| class="wikitable" style="font-size: 14px; background: white;" | ||
+ | |- | ||
+ | ! '''Note''' | ||
+ | | To be documented | ||
+ | |- | ||
+ | |} | ||
+ | </div></div> | ||
+ | <br /> | ||
+ | <div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;"> | ||
+ | <pre style="border: 0; padding-bottom:0px;">function SysI2CStart(Rate:LongWord):LongWord;</pre> | ||
+ | <div style="font-size: 14px; padding-left: 12px;">'''Description:''' Start the default I2C device ready for reading and writing</div> | ||
+ | <div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;"> | ||
+ | {| class="wikitable" style="font-size: 14px; background: white;" | ||
+ | |- | ||
+ | ! '''Rate''' | ||
+ | | The clock rate to set for the device (0 to use the default rate) | ||
+ | |- | ||
+ | ! '''Return''' | ||
+ | | ERROR_SUCCESS if completed or another error code on failure | ||
+ | |- | ||
+ | |} | ||
+ | </div></div> | ||
+ | <br /> | ||
+ | <div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;"> | ||
+ | <pre style="border: 0; padding-bottom:0px;">function SysI2CStop:LongWord;</pre> | ||
+ | <div style="font-size: 14px; padding-left: 12px;">'''Description:''' Stop the default I2C device and terminate reading and writing</div> | ||
+ | <div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;"> | ||
+ | {| class="wikitable" style="font-size: 14px; background: white;" | ||
+ | |- | ||
+ | ! '''Return''' | ||
+ | | ERROR_SUCCESS if completed or another error code on failure | ||
+ | |- | ||
+ | |} | ||
+ | </div></div> | ||
+ | <br /> | ||
+ | <div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;"> | ||
+ | <pre style="border: 0; padding-bottom:0px;">function SysI2CRead(Address:Word; Buffer:Pointer; Size:LongWord; var Count:LongWord):LongWord;</pre> | ||
+ | <div style="font-size: 14px; padding-left: 12px;">'''Description:''' Read data from the default I2C device</div> | ||
+ | <div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;"> | ||
+ | {| class="wikitable" style="font-size: 14px; background: white;" | ||
+ | |- | ||
+ | ! '''Address''' | ||
+ | | The slave address to read from (I2C_ADDRESS_INVALID to use the current address) | ||
+ | |- | ||
+ | ! '''Buffer''' | ||
+ | | Pointer to a buffer to receive the data | ||
+ | |- | ||
+ | ! '''Size''' | ||
+ | | The size of the buffer | ||
+ | |- | ||
+ | ! '''Count''' | ||
+ | | The number of bytes read on return | ||
+ | |- | ||
+ | ! '''Return''' | ||
+ | | ERROR_SUCCESS if completed or another error code on failure | ||
+ | |- | ||
+ | |} | ||
+ | </div></div> | ||
+ | <br /> | ||
+ | <div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;"> | ||
+ | <pre style="border: 0; padding-bottom:0px;">function SysI2CWrite(Address:Word; Buffer:Pointer; Size:LongWord; var Count:LongWord):LongWord;</pre> | ||
+ | <div style="font-size: 14px; padding-left: 12px;">'''Description:''' Write data to the default I2C device</div> | ||
+ | <div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;"> | ||
+ | {| class="wikitable" style="font-size: 14px; background: white;" | ||
+ | |- | ||
+ | ! '''Address''' | ||
+ | | The slave address to write to (I2C_ADDRESS_INVALID to use the current address) | ||
+ | |- | ||
+ | ! '''Buffer''' | ||
+ | | Pointer to a buffer of data to transmit | ||
+ | |- | ||
+ | ! '''Size''' | ||
+ | | The size of the buffer | ||
+ | |- | ||
+ | ! '''Count''' | ||
+ | | The number of bytes written on return | ||
+ | |- | ||
+ | ! '''Return''' | ||
+ | | ERROR_SUCCESS if completed or another error code on failure | ||
+ | |- | ||
+ | |} | ||
+ | </div></div> | ||
+ | <br /> | ||
+ | <div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;"> | ||
+ | <pre style="border: 0; padding-bottom:0px;">function SysI2CWriteRead(Address:Word; Initial:Pointer; Len:LongWord; Data:Pointer; Size:LongWord; var Count:LongWord):LongWord;</pre> | ||
+ | <div style="font-size: 14px; padding-left: 12px;">'''Description:''' Write data to and Read data from the default I2C device in one operation. Useful for devices that require a register address specified before a read (eg EEPROM devices)</div> | ||
+ | <div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;"> | ||
+ | {| class="wikitable" style="font-size: 14px; background: white;" | ||
+ | |- | ||
+ | ! '''Address''' | ||
+ | | The slave address to write to (I2C_ADDRESS_INVALID to use the current address) | ||
+ | |- | ||
+ | ! '''Initial''' | ||
+ | | Pointer to the initial buffer to transmit | ||
+ | |- | ||
+ | ! '''Len''' | ||
+ | | The size of the initial buffer | ||
+ | |- | ||
+ | ! '''Data''' | ||
+ | | Pointer to a buffer to receive the data | ||
+ | |- | ||
+ | ! '''Size''' | ||
+ | | The size of the data buffer | ||
+ | |- | ||
+ | ! '''Count''' | ||
+ | | The number of bytes read on return | ||
+ | |- | ||
+ | ! '''Return''' | ||
+ | | ERROR_SUCCESS if completed or another error code on failure | ||
+ | |- | ||
+ | |} | ||
+ | </div></div> | ||
+ | <br /> | ||
+ | <div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;"> | ||
+ | <pre style="border: 0; padding-bottom:0px;">function SysI2CWriteWrite(Address:Word; Initial:Pointer; Len:LongWord; Data:Pointer; Size:LongWord; var Count:LongWord):LongWord;</pre> | ||
+ | <div style="font-size: 14px; padding-left: 12px;">'''Description:''' Write 2 data blocks to the default I2C device in one operation. Useful for devices that require a register address specified before a write (eg EEPROM devices)</div> | ||
+ | <div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;"> | ||
+ | {| class="wikitable" style="font-size: 14px; background: white;" | ||
+ | |- | ||
+ | ! '''Address''' | ||
+ | | The slave address to write to (I2C_ADDRESS_INVALID to use the current address) | ||
+ | |- | ||
+ | ! '''Initial''' | ||
+ | | Pointer to the initial buffer to transmit | ||
+ | |- | ||
+ | ! '''Len''' | ||
+ | | The size of the initial buffer | ||
+ | |- | ||
+ | ! '''Data''' | ||
+ | | Pointer to a buffer of data to transmit | ||
+ | |- | ||
+ | ! '''Size''' | ||
+ | | The size of the data buffer | ||
+ | |- | ||
+ | ! '''Count''' | ||
+ | | The number of bytes of data written on return | ||
+ | |- | ||
+ | ! '''Return''' | ||
+ | | ERROR_SUCCESS if completed or another error code on failure | ||
+ | |- | ||
+ | |} | ||
+ | </div></div> | ||
+ | <br /> | ||
+ | <div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;"> | ||
+ | <pre style="border: 0; padding-bottom:0px;">function SysI2CGetRate:LongWord;</pre> | ||
+ | <div style="font-size: 14px; padding-left: 12px;">'''Description:''' Get the clock rate of the default I2C device</div> | ||
+ | <div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;"> | ||
+ | {| class="wikitable" style="font-size: 14px; background: white;" | ||
+ | |- | ||
+ | ! '''Return''' | ||
+ | | The clock rate in Hz or 0 on failure | ||
+ | |- | ||
+ | |} | ||
+ | </div></div> | ||
+ | <br /> | ||
+ | <div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;"> | ||
+ | <pre style="border: 0; padding-bottom:0px;">function SysI2CSetRate(Rate:LongWord):LongWord;</pre> | ||
+ | <div style="font-size: 14px; padding-left: 12px;">'''Description:''' Set the clock rate for the default I2C device</div> | ||
+ | <div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;"> | ||
+ | {| class="wikitable" style="font-size: 14px; background: white;" | ||
+ | |- | ||
+ | ! '''Rate''' | ||
+ | | The clock rate to set in Hz | ||
+ | |- | ||
+ | ! '''Return''' | ||
+ | | ERROR_SUCCESS if completed or another error code on failure | ||
+ | |- | ||
+ | |} | ||
+ | </div></div> | ||
+ | <br /> | ||
+ | <div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;"> | ||
+ | <pre style="border: 0; padding-bottom:0px;">function SysI2CGetAddress:Word; </pre> | ||
+ | <div style="font-size: 14px; padding-left: 12px;">'''Description:''' Get the slave address for the default I2C device</div> | ||
+ | <div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;"> | ||
+ | {| class="wikitable" style="font-size: 14px; background: white;" | ||
+ | |- | ||
+ | ! '''Return''' | ||
+ | | The slave address or I2C_ADDRESS_INVALID on failure | ||
+ | |- | ||
+ | |} | ||
+ | </div></div> | ||
+ | <br /> | ||
+ | <div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;"> | ||
+ | <pre style="border: 0; padding-bottom:0px;">function SysI2CSetAddress(Address:Word):LongWord;</pre> | ||
+ | <div style="font-size: 14px; padding-left: 12px;">'''Description:''' Set the slave address for the default I2C device</div> | ||
+ | <div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;"> | ||
+ | {| class="wikitable" style="font-size: 14px; background: white;" | ||
+ | |- | ||
+ | ! '''Address''' | ||
+ | | The slave address to set | ||
+ | |- | ||
+ | ! '''Return''' | ||
+ | | ERROR_SUCCESS if completed or another error code on failure | ||
|- | |- | ||
|} | |} |
Revision as of 06:04, 18 August 2016
Return to Unit Reference
Contents
[hide]Description
I2C (Inter-Integrated Circuit) is a serial bus for communication between peripheral components.
Originally invented by Phillips the I2C protocol is used by thousands of common chips that perform a wide range of tasks such as real time clocks, temperature and other sensors, small LCD displays and many more.
Each device is assigned a 7bit address which is used by the host (or master) to signal the device that a message written to the bus is intended for that device or that the host wants to read data from that device.
Speeds range from 10Kbps to 3.4Mbps although the typical speed is either 100Kbps or 400Kbps.
This unit implements the standardized interface for I2C devices and allows reading or writing to a specific address, setting a clock rate for the communication and determining device properties.
For the purpose of this interface a device is the I2C controller attached to the local system and may be either a master or a slave. Since the protocol does not include any form of enumeration or identification the interface does not attempt to represent the devices connected to the bus,any driver written to communicate with a connected I2C device should know (or allow configuration of) the address to read and write to and the specific message format required for that device. The Intel System Management Bus (SMBus) is a variation of the I2C bus and in certain cases the two are compatible with each other.
Constants
To be documented
Type definitions
To be documented
Public variables
To be documented
Function declarations
Initialization functions
I2C functions
function I2CDeviceStart(I2C:PI2CDevice; Rate:LongWord):LongWord;
function I2CDeviceStop(I2C:PI2CDevice):LongWord;
function I2CDeviceRead(I2C:PI2CDevice; Address:Word; Buffer:Pointer; Size:LongWord; var Count:LongWord):LongWord;
function I2CDeviceWrite(I2C:PI2CDevice; Address:Word; Buffer:Pointer; Size:LongWord; var Count:LongWord):LongWord;
function I2CDeviceWriteRead(I2C:PI2CDevice; Address:Word; Initial:Pointer; Len:LongWord; Data:Pointer; Size:LongWord; var Count:LongWord):LongWord;
function I2CDeviceWriteWrite(I2C:PI2CDevice; Address:Word; Initial:Pointer; Len:LongWord; Data:Pointer; Size:LongWord; var Count:LongWord):LongWord;
function I2CDeviceGetRate(I2C:PI2CDevice):LongWord;
function I2CDeviceSetRate(I2C:PI2CDevice; Rate:LongWord):LongWord;
function I2CDeviceGetAddress(I2C:PI2CDevice):Word;
function I2CDeviceSetAddress(I2C:PI2CDevice; Address:Word):LongWord;
function I2CDeviceProperties(I2C:PI2CDevice; Properties:PI2CProperties):LongWord;
function I2CDeviceDestroy(I2C:PI2CDevice):LongWord;
function I2CDeviceRegister(I2C:PI2CDevice):LongWord;
function I2CDeviceDeregister(I2C:PI2CDevice):LongWord;
function I2CDeviceFindByName(const Name:String):PI2CDevice; inline;
function I2CDeviceFindByDescription(const Description:String):PI2CDevice; inline;
function I2CDeviceEnumerate(Callback:TI2CEnumerate; Data:Pointer):LongWord;
function I2CDeviceNotification(I2C:PI2CDevice; Callback:TI2CNotification; Data:Pointer; Notification,Flags:LongWord):LongWord;
RTL I2C functions
function SysI2CStart(Rate:LongWord):LongWord;
function SysI2CStop:LongWord;
function SysI2CRead(Address:Word; Buffer:Pointer; Size:LongWord; var Count:LongWord):LongWord;
function SysI2CWrite(Address:Word; Buffer:Pointer; Size:LongWord; var Count:LongWord):LongWord;
function SysI2CWriteRead(Address:Word; Initial:Pointer; Len:LongWord; Data:Pointer; Size:LongWord; var Count:LongWord):LongWord;
function SysI2CWriteWrite(Address:Word; Initial:Pointer; Len:LongWord; Data:Pointer; Size:LongWord; var Count:LongWord):LongWord;
function SysI2CSetRate(Rate:LongWord):LongWord;
function SysI2CGetAddress:Word;
function SysI2CSetAddress(Address:Word):LongWord;
Return to Unit Reference