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typedef void(* | printfCb )(char *buf, int32_t *indicator, char val, int len) |
| A function pointer which is used when format printf log.
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int | StrFormatPrintf (const char *fmt, va_list ap, char *buf, printfCb cb) |
| This function outputs its parameters according to a formatted string. More...
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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...
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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. The below picture shows the laylout of debug console.
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.
Select the supported debug console hardware device type, such as
typedef enum _serial_port_type
{
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.
DbgConsole_Init(BOARD_DEBUG_UART_INSTANCE, BOARD_DEBUG_UART_BAUDRATE, BOARD_DEBUG_UART_TYPE,
BOARD_DEBUG_UART_CLK_FREQ);
Advanced Feature
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 |
Do not support |
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.
This utility supports selecting toolchain's printf/scanf or the MCUXpresso SDK printf/scanf.
#if SDK_DEBUGCONSOLE == DEBUGCONSOLE_DISABLE
#define PRINTF
#define SCANF
#define PUTCHAR
#define GETCHAR
#elif SDK_DEBUGCONSOLE == DEBUGCONSOLE_REDIRECT_TO_SDK
#define PRINTF DbgConsole_Printf
#define SCANF DbgConsole_Scanf
#define PUTCHAR DbgConsole_Putchar
#define GETCHAR DbgConsole_Getchar
#elif SDK_DEBUGCONSOLE == DEBUGCONSOLE_REDIRECT_TO_TOOLCHAIN
#define PRINTF printf
#define SCANF scanf
#define PUTCHAR putchar
#define GETCHAR getchar
#endif
NOTE: The macro SDK_DEBUGCONSOLE_UART is use to decide whether provide low level IO implementation to toolchain printf and scanf. For example, within MCUXpresso, if the macro SDK_DEBUGCONSOLE_UART is defined, sys_write and __sys_readc will be used when __REDLIB is defined; _write and _read will be used in other cases. If the macro SDK_DEBUGCONSOLE_UART is not defined, the semihosting will be used.
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.
#define DEBUGCONSOLE_REDIRECT_TO_TOOLCHAIN 0U |
Select toolchain printf and scanf.
#define DEBUGCONSOLE_REDIRECT_TO_SDK 1U |
#define DEBUGCONSOLE_DISABLE 2U |
#define SDK_DEBUGCONSOLE 1U |
The macro only support to be redefined in project setting.
if SDK_DEBUGCONSOLE defined to 0,it represents select toolchain printf, scanf. if SDK_DEBUGCONSOLE defined to 1,it represents select SDK version printf, scanf. if SDK_DEBUGCONSOLE defined to 2,it represents disable debugconsole function.
Call this function to enable debug log messages to be output via the specified peripheral initialized by the serial manager module. After this function has returned, stdout and stdin are connected to the selected peripheral.
- Parameters
-
instance | The instance of the module. |
baudRate | The desired baud rate in bits per second. |
device | Low level device type for the debug console, can be one of the following.
- kSerialPort_Uart,
- kSerialPort_UsbCdc
- kSerialPort_UsbCdcVirtual.
|
clkSrcFreq | Frequency of peripheral source clock. |
- Returns
- Indicates whether initialization was successful or not.
- Return values
-
kStatus_Success | Execution successfully |
Call this function to disable debug log messages to be output via the specified peripheral initialized by the serial manager module.
- Returns
- Indicates whether de-initialization was successful or not.
int DbgConsole_Printf |
( |
const char * |
formatString, |
|
|
|
... |
|
) |
| |
Call this function to write a formatted output to the standard output stream.
- Parameters
-
formatString | 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 * |
formatString, |
|
|
|
... |
|
) |
| |
Call this function to read formatted data from the standard input stream.
- Note
- Due the limitation in the BM OSA environment (CPU is blocked in the function, other tasks will not be scheduled), the function cannot be used when the DEBUG_CONSOLE_TRANSFER_NON_BLOCKING is set in the BM OSA environment. And an error is returned when the function called in this case. The suggestion is that polling the non-blocking function DbgConsole_TryGetchar to get the input char.
- Parameters
-
formatString | 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.
- Note
- Due the limitation in the BM OSA environment (CPU is blocked in the function, other tasks will not be scheduled), the function cannot be used when the DEBUG_CONSOLE_TRANSFER_NON_BLOCKING is set in the BM OSA environment. And an error is returned when the function called in this case. The suggestion is that polling the non-blocking function DbgConsole_TryGetchar to get the input char.
- Returns
- Returns the character read.
int DbgConsole_BlockingPrintf |
( |
const char * |
formatString, |
|
|
|
... |
|
) |
| |
Call this function to write a formatted output to the standard output stream with the blocking mode. The function will send data with blocking mode no matter the DEBUG_CONSOLE_TRANSFER_NON_BLOCKING set or not. The function could be used in system ISR mode with DEBUG_CONSOLE_TRANSFER_NON_BLOCKING set.
- Parameters
-
formatString | Format control string. |
- Returns
- Returns the number of characters printed or a negative value if an error occurs.
Call this function to wait the tx buffer empty. 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.
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 | Format string for printf. |
[in] | ap | 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 "". |