Detailed Description

I2C driver implementation for a Low Power F3 device I2C controller.

Driver Include

The I2C header file should be included in an application as follows:

#include <ti/drivers/I2C.h>

#include <ti/drivers/i2c/I2CLPF3.h>

Overview

Refer to I2C.h for a complete description of APIs.

General Behavior

Before using the I2C in LPF3:

The I2C driver is initialized by calling I2C_init().
The I2C HW is configured and system dependencies are declared (e.g. IOs, power, etc.) by calling I2C_open().

The following is true for receive operation:

RX is enabled by calling I2C_transfer(). The readCount of the I2C_Transaction must be set to a non-zero value.
If the I2C_transfer() succeeds, the I2C remains enabled.
The application must check the return value from I2C_transfer() to verify that the transfer succeeded.

The following apply for transmit operation:

TX is enabled by calling I2C_transfer(). The writeCount of the I2C_Transaction must be set to a non-zero value.
If the I2C_transfer() succeeds, the I2C remains enabled.
The application must check the return value from I2C_transfer() to verify that the transfer succeeded.

After I2C operation has ended:

Release system dependencies for I2C by calling I2C_close().

Known Issue

Warning: The I2C will transmit a single data byte in the event that the I2C target address is not acknowledged (NACK'd). This is due to a known hardware bug.

Error handling

If an error occurs during operation:

The I2C Controller transmits a stop bit and remains enabled.

Power Management

The I2CLPF3 driver sets a power constraint during transactions to keep the device out of standby; so when all tasks are blocked, the device will enter idle mode instead of standby. When the transactions have finished, the power constraint to prohibit standby is released. The following statements are valid:

After I2C_open() call: I2C is enabled, there are no active I2C transactions, the device can enter standby.
After I2C_transfer() call: active I2C transactions exist, the device might enter idle, but not standby.
When I2C_transfer() completes, either after success or error, I2C remains enabled, and the device can enter standby.
After I2C_close() call: I2C is disabled
If the device goes into idle during a transaction, the state of SDA is undefined in the time between the transaction completing and the device waking up. SCL will go low until the device wakes up and starts another transaction or releases the bus. If this is a problem for another device on the I2C bus, you can set a power constraint for PowerLPF3_DISALLOW_IDLE before the transaction and release it when the transaction completes.

Supported Functions

Generic API Function	Description
I2C_init()	Initialize I2C driver
I2C_Params_init()	Initialize an I2C_Params structure
I2C_open()	Initialize I2C HW and set system dependencies
I2C_close()	Disable I2C HW and release system dependencies
I2C_transfer()	Start I2C transfer
I2C_transferTimeout()	Start I2C transfer with a timeout
I2C_cancel()	Cancels all I2C transfers

Supported Bit Rates

Supported Address Modes

I2C_ADDRESS_MODE_7_BIT

Unsupported Functionality

The LPF3 I2C driver currently does not support:

Multi-controller mode
I2C target mode

Instrumentation

The I2C driver interface produces log statements if instrumentation is enabled.

Diagnostics Mask	Log details
Diags_USER1	basic I2C operations performed
Diags_USER2	detailed I2C operations performed

#include <stdint.h>
#include <stdbool.h>
#include <ti/drivers/I2C.h>
#include <ti/drivers/Power.h>
#include <ti/drivers/dpl/SwiP.h>

Include dependency graph for I2CLPF3.h:

Go to the source code of this file.

Data Structures
struct	I2CLPF3_I2CPinCfg
	I2CLPF3 Pin Configuration. More...

struct	I2CLPF3_HWAttrs
	I2CLPF3 Hardware attributes. More...

struct	I2CLPF3_Object
	I2CLPF3 Object. More...