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UART driver implementation for a CC32XX UART controller.
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The UART header file should be included in an application as follows:
Refer to UART.h for a complete description of APIs & example of use.
The UARTCC32XX driver is (ring) buffered driver, and stores data it may have already received in a user-supplied background buffer.
While permitted, it is STRONGLY suggested to avoid implementations where you call UART_read() within its own callback function (when in UART_MODE_CALLBACK). Doing so, will require additional (task and system) stack for each nested UART_read() call.
| Tool chain | Number of bytes per nested UART_read() call |
|---|---|
| GNU | 96 bytes + callback function stack requirements |
| IAR | 40 bytes + callback function stack requirements |
| TI | 80 bytes + callback function stack requirements |
It is important to note a potential worst case scenario: A full ring buffer with data; say 32 bytes The callback function calls UART_read() with a size of 1 (byte) No other variables are allocated in the callback function No other function calls are made in the callback function
As a result, you need an additional task and system stack of: 32 bytes * (80 bytes for TI + 0 bytes by the callback function) = 2.5kB
This header file contains pin mode definitions used to specify the UART TX and RX pin assignment in the UARTCC32XX_HWAttrsV1 structure. Please refer to the CC32XX Techincal Reference Manual for details on pin multiplexing. The bits in the pin mode macros are as follows: The lower 8 bits of the macro refer to the pin, offset by 1, to match driverlib pin defines. For example, UARTCC32XX_PIN_01_UART1_TX & 0xff = 0, which equals PIN_01 in driverlib pin.h. By matching the PIN_xx defines in driverlib pin.h, we can pass the pin directly to the driverlib functions. The upper 8 bits of the macro correspond to the pin mux confg mode value for the pin to operate in the UART mode. For example, pin 1 is configured with mode 7 to operate as UART1 TX.
To enable Flow Control, the RTS and CTS pins must be assigned in the UARTCC32XX_HWAttrsV1.
#include <stdint.h>#include <stdbool.h>#include <ti/drivers/dpl/ClockP.h>#include <ti/drivers/dpl/HwiP.h>#include <ti/drivers/dpl/SemaphoreP.h>#include <ti/drivers/Power.h>#include <ti/drivers/power/PowerCC32XX.h>#include <ti/drivers/UART.h>#include <ti/drivers/utils/RingBuf.h>Go to the source code of this file.
Data Structures | |
| struct | UARTCC32XX_FxnSet |
| Complement set of read functions to be used by the UART ISR and UARTCC32XX_read(). Internal use only. More... | |
| struct | UARTCC32XX_HWAttrsV1 |
| UARTCC32XX Hardware attributes. More... | |
| struct | UARTCC32XX_Object |
| UARTCC32XX Object. More... | |
Typedefs | |
| typedef struct UARTCC32XX_FxnSet | UARTCC32XX_FxnSet |
| Complement set of read functions to be used by the UART ISR and UARTCC32XX_read(). Internal use only. More... | |
| typedef struct UARTCC32XX_HWAttrsV1 | UARTCC32XX_HWAttrsV1 |
| UARTCC32XX Hardware attributes. More... | |
| typedef struct UARTCC32XX_Object | UARTCC32XX_Object |
| UARTCC32XX Object. More... | |
| typedef struct UARTCC32XX_Object * | UARTCC32XX_Handle |
Variables | |
| const UART_FxnTable | UARTCC32XX_fxnTable |
| #define UARTCC32XX_PIN_UNASSIGNED 0xFFF |
Indicates a pin is not being used.
If hardware flow control is not being used, the UART CTS and RTS pins should be set to UARTCC32XX_PIN_UNASSIGNED.
| #define UARTCC32XX_PIN_01_UART1_TX 0x700 |
| #define UARTCC32XX_PIN_02_UART1_RX 0x701 |
| #define UARTCC32XX_PIN_03_UART0_TX 0x702 |
| #define UARTCC32XX_PIN_04_UART0_RX 0x703 |
| #define UARTCC32XX_PIN_07_UART1_TX 0x506 |
| #define UARTCC32XX_PIN_08_UART1_RX 0x507 |
| #define UARTCC32XX_PIN_16_UART1_TX 0x20F |
| #define UARTCC32XX_PIN_17_UART1_RX 0x210 |
| #define UARTCC32XX_PIN_45_UART0_RX 0x92C |
| #define UARTCC32XX_PIN_45_UART1_RX 0x22C |
| #define UARTCC32XX_PIN_53_UART0_TX 0x934 |
| #define UARTCC32XX_PIN_55_UART0_TX 0x336 |
| #define UARTCC32XX_PIN_55_UART1_TX 0x636 |
| #define UARTCC32XX_PIN_57_UART0_RX 0x338 |
| #define UARTCC32XX_PIN_57_UART1_RX 0x638 |
| #define UARTCC32XX_PIN_58_UART1_TX 0x639 |
| #define UARTCC32XX_PIN_59_UART1_RX 0x63A |
| #define UARTCC32XX_PIN_62_UART0_TX 0xB3D |
| #define UARTCC32XX_PIN_50_UART1_RTS 0xA31 |
| #define UARTCC32XX_PIN_61_UART1_CTS 0x33C |
| #define UARTCC32XX_PIN_62_UART1_RTS 0x33D |
| #define UARTCC32XX_FLOWCTRL_NONE 0 |
No hardware flow control.
| #define UARTCC32XX_FLOWCTRL_HARDWARE 1 |
Hardware flow control.
| typedef struct UARTCC32XX_FxnSet UARTCC32XX_FxnSet |
Complement set of read functions to be used by the UART ISR and UARTCC32XX_read(). Internal use only.
These functions are solely intended for the UARTCC32XX driver, and should not be used by the application. The UARTCC32XX_FxnSet is a pair of complement functions that are design to operate with one another in a task context and in an ISR context. The readTaskFxn is called by UARTCC32XX_read() to drain a circular buffer, whereas the readIsrFxn is used by the UARTCC32XX_hwiIntFxn to fill up the circular buffer.
readTaskFxn: Function called by UART read These variables are set and avilalable for use to the readTaskFxn. object->readBuf = buffer; //Pointer to a user buffer object->readSize = size; //Desired no. of bytes to read object->readCount = size; //Remaining no. of bytes to read
readIsrFxn: The required ISR counterpart to readTaskFxn
| typedef struct UARTCC32XX_HWAttrsV1 UARTCC32XX_HWAttrsV1 |
UARTCC32XX Hardware attributes.
The fields, baseAddr, intNum, and flowControl, are used by driverlib APIs and therefore must be populated by driverlib macro definitions. For CC32XXWare these definitions are found in:
intPriority is the UART peripheral's interrupt priority, as defined by the underlying OS. It is passed unmodified to the underlying OS's interrupt handler creation code, so you need to refer to the OS documentation for usage. For example, for SYS/BIOS applications, refer to the ti.sysbios.family.arm.m3.Hwi documentation for SYS/BIOS usage of interrupt priorities. If the driver uses the ti.dpl interface instead of making OS calls directly, then the HwiP port handles the interrupt priority in an OS specific way. In the case of the SYS/BIOS port, intPriority is passed unmodified to Hwi_create().
A sample structure is shown below:
| typedef struct UARTCC32XX_Object UARTCC32XX_Object |
UARTCC32XX Object.
The application must not access any member variables of this structure!
| typedef struct UARTCC32XX_Object * UARTCC32XX_Handle |
| const UART_FxnTable UARTCC32XX_fxnTable |