Overview

This chapter describes the programming interface of the debug console driver.

The debug console enables debug log messages to be output via the specified peripheral with frequency of the peripheral source clock and base address at the specified baud rate. Additionally, it provides input and output functions to scan and print formatted data.It is consist of log, str, io. Log layer is used to handle the formatted log, push log to buffer or flush log to IO. STR layer is used to format the printf and scanf log. IO layer is a warpper of various uart peripheral.

Function groups

Initialization

To initialize the debug console, call the DbgConsole_Init() function with these parameters. This function automatically enables the module and the clock.

/*
 * @brief Initializes the peripheral used to debug messages.
 *
 * @param baseAddr      Indicates which address of the peripheral is used to send debug messages.
 * @param baudRate      The desired baud rate in bits per second.
 * @param device        Low level device type for the debug console, can be one of:
 *                      @arg DEBUG_CONSOLE_DEVICE_TYPE_UART,
 *                      @arg DEBUG_CONSOLE_DEVICE_TYPE_LPUART,
 *                      @arg DEBUG_CONSOLE_DEVICE_TYPE_LPSCI,
 *                      @arg DEBUG_CONSOLE_DEVICE_TYPE_USBCDC.
 * @param clkSrcFreq    Frequency of peripheral source clock.
 *
 * @return              Whether initialization was successful or not.
 */
status_t DbgConsole_Init(uint32_t baseAddr, uint32_t baudRate, uint8_t device, uint32_t clkSrcFreq)

Selects the supported debug console hardware device type, such as

DEBUG_CONSOLE_DEVICE_TYPE_NONE   
DEBUG_CONSOLE_DEVICE_TYPE_LPSCI  
DEBUG_CONSOLE_DEVICE_TYPE_UART   
DEBUG_CONSOLE_DEVICE_TYPE_LPUART 
DEBUG_CONSOLE_DEVICE_TYPE_USBCDC 

After the initialization is successful, stdout and stdin are connected to the selected peripheral.

This example shows how to call the DbgConsole_Init() given the user configuration structure.

uint32_t uartClkSrcFreq = CLOCK_GetFreq(BOARD_DEBUG_UART_CLKSRC);
DbgConsole_Init(BOARD_DEBUG_UART_BASEADDR, BOARD_DEBUG_UART_BAUDRATE, DEBUG_CONSOLE_DEVICE_TYPE_UART, uartClkSrcFreq);

Advanced Features

The debug console provides input and output functions to scan and print formatted data.

Support a format specifier for PRINTF following this prototype " %[flags][width][.precision][length]specifier", which is explained below

flags	Description
-	Left-justified within the given field width. Right-justified is the default.
+	Forces to precede the result with a plus or minus sign (+ or -) even for positive numbers. By default, only negative numbers are preceded with a - sign.
(space)	If no sign is written, a blank space is inserted before the value.
#	Used with o, x, or X specifiers the value is preceded with 0, 0x, or 0X respectively for values other than zero. Used with e, E and f, it forces the written output to contain a decimal point even if no digits would follow. By default, if no digits follow, no decimal point is written. Used with g or G the result is the same as with e or E but trailing zeros are not removed.
0	Left-pads the number with zeroes (0) instead of spaces, where padding is specified (see width sub-specifier).

Width	Description
(number)	A minimum number of characters to be printed. If the value to be printed is shorter than this number, the result is padded with blank spaces. The value is not truncated even if the result is larger.
*	The width is not specified in the format string, but as an additional integer value argument preceding the argument that has to be formatted.

.precision

Description

.number

For integer specifiers (d, i, o, u, x, X) − precision specifies the minimum number of digits to be written. If the value to be written is shorter than this number, the result is padded with leading zeros. The value is not truncated even if the result is longer. A precision of 0 means that no character is written for the value 0. For e, E, and f specifiers − this is the number of digits to be printed after the decimal point. For g and G specifiers − This is the maximum number of significant digits to be printed. For s − this is the maximum number of characters to be printed. By default, all characters are printed until the ending null character is encountered. For c type − it has no effect. When no precision is specified, the default is 1. If the period is specified without an explicit value for precision, 0 is assumed.

.*

The precision is not specified in the format string, but as an additional integer value argument preceding the argument that has to be formatted.

length	Description
Not supported

specifier	Description
d or i	Signed decimal integer
f	Decimal floating point
F	Decimal floating point capital letters
x	Unsigned hexadecimal integer
X	Unsigned hexadecimal integer capital letters
o	Signed octal
b	Binary value
p	Pointer address
u	Unsigned decimal integer
c	Character
s	String of characters
n	Nothing printed

Support a format specifier for SCANF following this prototype " %[*][width][length]specifier", which is explained below

*	Description
An optional starting asterisk indicates that the data is to be read from the stream but ignored. In other words, it is not stored in the corresponding argument.

width	Description
This specifies the maximum number of characters to be read in the current reading operation.

length	Description
hh	The argument is interpreted as a signed character or unsigned character (only applies to integer specifiers: i, d, o, u, x, and X).
h	The argument is interpreted as a short integer or unsigned short integer (only applies to integer specifiers: i, d, o, u, x, and X).
l	The argument is interpreted as a long integer or unsigned long integer for integer specifiers (i, d, o, u, x, and X) and as a wide character or wide character string for specifiers c and s.
ll	The argument is interpreted as a long long integer or unsigned long long integer for integer specifiers (i, d, o, u, x, and X) and as a wide character or wide character string for specifiers c and s.
L	The argument is interpreted as a long double (only applies to floating point specifiers: e, E, f, g, and G).
j or z or t	Not supported

specifier	Qualifying Input	Type of argument
c	Single character: Reads the next character. If a width different from 1 is specified, the function reads width characters and stores them in the successive locations of the array passed as argument. No null character is appended at the end.	char *
i	Integer: : Number optionally preceded with a + or - sign	int *
d	Decimal integer: Number optionally preceded with a + or - sign	int *
a, A, e, E, f, F, g, G	Floating point: Decimal number containing a decimal point, optionally preceded by a + or - sign and optionally followed by the e or E character and a decimal number. Two examples of valid entries are -732.103 and 7.12e4	float *
o	Octal Integer:	int *
s	String of characters. This reads subsequent characters until a white space is found (white space characters are considered to be blank, newline, and tab).	char *
u	Unsigned decimal integer.	unsigned int *

The debug console has its own printf/scanf/putchar/getchar functions which are defined in the header file.

int DbgConsole_Printf(const char *fmt_s, ...);  
int DbgConsole_Putchar(int ch);                 
int DbgConsole_Scanf(const char *fmt_ptr, ...); 
int DbgConsole_Getchar(void);                   

This utility supports selecting toolchain's printf/scanf or the MCUXpresso SDK printf/scanf.

#if SDK_DEBUGCONSOLE    /* Select printf, scanf, putchar, getchar of SDK version. */
#define PRINTF                 DbgConsole_Printf
#define SCANF                  DbgConsole_Scanf
#define PUTCHAR                DbgConsole_Putchar
#define GETCHAR                DbgConsole_Getchar
#else                   /* Select printf, scanf, putchar, getchar of toolchain. */
#define PRINTF                 printf
#define SCANF                  scanf
#define PUTCHAR                putchar
#define GETCHAR                getchar
#endif /* SDK_DEBUGCONSOLE */

Typical use case

Some examples use the PUTCHAR & GETCHAR function

ch = GETCHAR();

PUTCHAR(ch);

Some examples use the PRINTF function

Statement prints the string format.

PRINTF("%s %s\r\n", "Hello", "world!");

Statement prints the hexadecimal format/

PRINTF("0x%02X hexadecimal number equivalents 255", 255);

Statement prints the decimal floating point and unsigned decimal.

PRINTF("Execution timer: %s\n\rTime: %u ticks %2.5f milliseconds\n\rDONE\n\r", "1 day", 86400, 86.4);

Some examples use the SCANF function

PRINTF("Enter a decimal number: ");
SCANF("%d", &i);
PRINTF("\r\nYou have entered %d.\r\n", i, i);
PRINTF("Enter a hexadecimal number: ");
SCANF("%x", &i);
PRINTF("\r\nYou have entered 0x%X (%d).\r\n", i, i);

Print out failure messages using MCUXpresso SDK __assert_func:

void __assert_func(const char *file, int line, const char *func, const char *failedExpr)
{
    PRINTF("ASSERT ERROR \" %s \": file \"%s\" Line \"%d\" function name \"%s\" \n", failedExpr, file , line, func);
    for (;;)
    {}
}

Note:

To use 'printf' and 'scanf' for GNUC Base, add file 'fsl_sbrk.c' in path: ..\{package}\devices\{subset}\utilities\fsl_sbrk.c to your project.

Modules
	Semihosting

Data Structures
struct	io_state_t
	State structure storing io. More...

Macros
#define	SDK_DEBUGCONSOLE 1U
	Definition to select sdk or toolchain printf, scanf. More...

Typedefs
typedef void(*	notify )(size_t *size, bool rx, bool tx)
	define a notify callback for IO More...

typedef void(*	printfCb )(char buf, int32_t indicator, char val, int len)
	A function pointer which is used when format printf log.

Functions
void	IO_Init (io_state_t io, uint32_t baudRate, uint32_t clkSrcFreq, uint8_t ringBuffer)
	io init function. More...

status_t	IO_Deinit (void)
	Deinit IO. More...

status_t	IO_Transfer (uint8_t *ch, size_t size, bool tx)
	io transfer function. More...

status_t	IO_WaitIdle (void)
	io wait idle. More...

status_t	LOG_Init (uint32_t baseAddr, uint8_t device, uint32_t baudRate, uint32_t clkSrcFreq)
	Initializes. More...

void	LOG_Deinit (void)
	De-Initializes. More...

int	LOG_Push (uint8_t *buf, size_t size)
	log push interface More...

int	LOG_ReadLine (uint8_t *buf, size_t size)
	log read one line function More...

int	LOG_ReadCharacter (uint8_t *ch)
	log read one character function More...

status_t	LOG_WaitIdle (void)
	wait log and io idle More...

int	LOG_Pop (uint8_t *buf, size_t size)
	log pop function More...

int	StrFormatPrintf (const char fmt, va_list ap, char buf, printfCb cb)
	This function outputs its parameters according to a formatted string. More...

int	StrFormatScanf (const char line_ptr, char format, va_list args_ptr)
	Converts an input line of ASCII characters based upon a provided string format. More...

Initialization
status_t	DbgConsole_Init (uint32_t baseAddr, uint32_t baudRate, uint8_t device, uint32_t clkSrcFreq)
	Initializes the the peripheral used for debug messages. More...

status_t	DbgConsole_Deinit (void)
	De-initializes the peripheral used for debug messages. More...

int	DbgConsole_Printf (const char *fmt_s,...)
	Writes formatted output to the standard output stream. More...

int	DbgConsole_Putchar (int ch)
	Writes a character to stdout. More...

int	DbgConsole_Scanf (char *fmt_ptr,...)
	Reads formatted data from the standard input stream. More...

int	DbgConsole_Getchar (void)
	Reads a character from standard input. More...

status_t	DbgConsole_Flush (void)
	Debug console flush log. More...

Data Structure Documentation

struct io_state_t

Data Fields
void *	ioBase
	Base of the IP register. More...

uint8_t	ioType
	device type

Field Documentation

void* io_state_t::ioBase

Macro Definition Documentation

#define SDK_DEBUGCONSOLE 1U

Typedef Documentation

typedef void(* notify)(size_t *size, bool rx, bool tx)

Parameters

size,transfer	data size.
rx,indicate	a rx transfer is success.
tx,indicate	a tx transfer is success.

Function Documentation

status_t DbgConsole_Init	(	uint32_t	baseAddr,
		uint32_t	baudRate,
		uint8_t	device,
		uint32_t	clkSrcFreq
	)

Call this function to enable debug log messages to be output via the specified peripheral, frequency of peripheral source clock, and base address at the specified baud rate. After this function has returned, stdout and stdin are connected to the selected peripheral.

Parameters

baseAddr	Indicates the address of the peripheral used to send debug messages.
baudRate	The desired baud rate in bits per second.
device	Low level device type for the debug console, can be one of the following. DEBUG_CONSOLE_DEVICE_TYPE_UART, DEBUG_CONSOLE_DEVICE_TYPE_LPUART, DEBUG_CONSOLE_DEVICE_TYPE_LPSCI, DEBUG_CONSOLE_DEVICE_TYPE_USBCDC.
clkSrcFreq	Frequency of peripheral source clock.

Returns: Indicates whether initialization was successful or not.

Return values

kStatus_Success	Execution successfully
kStatus_Fail	Execution failure
kStatus_InvalidArgument	Invalid argument existed

status_t DbgConsole_Deinit ( void )

Call this function to disable debug log messages to be output via the specified peripheral base address and at the specified baud rate.

Returns: Indicates whether de-initialization was successful or not.

int DbgConsole_Printf	(	const char *	fmt_s,
			...
	)

Call this function to write a formatted output to the standard output stream.

Parameters

fmt_s Format control string.

Returns: Returns the number of characters printed or a negative value if an error occurs.

int DbgConsole_Putchar ( int ch )

Call this function to write a character to stdout.

Parameters

ch	Character to be written.

Returns: Returns the character written.

int DbgConsole_Scanf	(	char *	fmt_ptr,
			...
	)

Call this function to read formatted data from the standard input stream.

Parameters

fmt_ptr Format control string.

Returns: Returns the number of fields successfully converted and assigned.

int DbgConsole_Getchar ( void )

Call this function to read a character from standard input.

Returns: Returns the character read.

status_t DbgConsole_Flush ( void )

Call this function to wait the buffer empty and io idle before. If interrupt transfer is using, make sure the global IRQ is enable before call this function This function should be called when 1, before enter power down mode 2, log is required to print to terminal immediately

Returns: Indicates whether wait idle was successful or not.

void IO_Init	(	io_state_t *	io,
		uint32_t	baudRate,
		uint32_t	clkSrcFreq,
		uint8_t *	ringBuffer
	)

Call this function to init IO.

Parameters

io	configuration pointer
baudRate	baud rate
clkSrcFreq	clock freq
ringbuffer	used to receive character

status_t IO_Deinit ( void )

Call this function to Deinit IO.

Returns: deinit status

status_t IO_Transfer	(	uint8_t *	ch,
		size_t	size,
		bool	tx
	)

Call this function to transfer log. Print log:

* IO_Transfer(ch, size, true);

*

Scanf log:

* IO_Transfer(ch, size, false);

*

Parameters

ch	transfer buffer pointer
size	transfer size
tx	indicate the transfer is TX or RX

status_t IO_WaitIdle ( void )

Call this function to wait the io idle

Returns: Indicates whether wait idle was successful or not.

status_t LOG_Init	(	uint32_t	baseAddr,
		uint8_t	device,
		uint32_t	baudRate,
		uint32_t	clkSrcFreq
	)

Call this function to init the buffer

Parameters

baseAddr,device	base address
device,device	type
baudRate,device	communicate baudrate
clkSrcFreq,device	source clock freq

Returns: Indicates whether initialization was successful or not.

Return values

kStatus_Success	Execution successfully
kStatus_Fail	Execution failure

void LOG_Deinit ( void )

Call this function to deinit the buffer

Returns: Indicates whether Deinit was successful or not.

int LOG_Push	(	uint8_t *	buf,
		size_t	size
	)

Call this function to print log

Parameters

fmt,buffer	pointer
size,avaliable	size

Returns: indicate the push size

Return values

	indicate buffer is full or transfer fail.
size	return the push log size.

int LOG_ReadLine	(	uint8_t *	buf,
		size_t	size
	)

Call this function to print log

Parameters

fmt,buffer	pointer
size,avaliable	size the number of the recieved character

int LOG_ReadCharacter ( uint8_t * ch )

Call this function to GETCHAR

Parameters

ch	receive address the number of the recieved character

status_t LOG_WaitIdle ( void )

Call this function to wait log buffer empty and io idle before enter low power mode.

Returns: Indicates whether wait idle was successful or not.

int LOG_Pop	(	uint8_t *	buf,
		size_t	size
	)

Call this function to pop log from buffer.

Parameters

buf	buffer address to pop
size	log size to pop

Returns: pop log size.

int StrFormatPrintf	(	const char *	fmt,
		va_list	ap,
		char *	buf,
		printfCb	cb
	)

Note: I/O is performed by calling given function pointer using following (*func_ptr)(c);

Parameters

[in]	fmt_ptr	Format string for printf.
[in]	args_ptr	Arguments to printf.
[in]	buf	pointer to the buffer
	cb	print callbck function pointer

Returns: Number of characters to be print

int StrFormatScanf	(	const char *	line_ptr,
		char *	format,
		va_list	args_ptr
	)

Parameters

[in]	line_ptr	The input line of ASCII data.
[in]	format	Format first points to the format string.
[in]	args_ptr	The list of parameters.

Returns: Number of input items converted and assigned.

Return values

IO_EOF When line_ptr is empty string "".

Overview

Function groups

Initialization

Advanced Features

Typical use case

Some examples use the PUTCHAR & GETCHAR function

Some examples use the PRINTF function

Some examples use the SCANF function

Print out failure messages using MCUXpresso SDK __assert_func:

Note:

Modules

Data Structures

Macros

Typedefs

Functions

Initialization

Data Structure Documentation

Data Fields

Field Documentation

Macro Definition Documentation

Typedef Documentation

Function Documentation