Functions
NUTFILE *	LpcDevDebugOpen (NUTDEVICE dev, const char name, int mode, int acc)
	Open debug device.
int	LpcDevDebugClose (NUTFILE *fp)
	Close debug device.
int	LpcDevDebugIOCtl (NUTDEVICE dev, int req, void conf)
	Handle I/O controls for debug device 2.
int	LpcDevDebugWrite (NUTFILE fp, const void buffer, int len)
	Send characters to debug device 0.
Variables
NUTDEVICE	devDebug0
	Debug device 0 information structure.

Function Documentation

NUTFILE* LpcDevDebugOpen	(	NUTDEVICE *	dev,
		const char *	name,
		int	mode,
		int	acc
	)

Open debug device.

Parameters:

dev	Pointer to a previously registered NUTDEVICE structure.
name	Ignored, typically points to an empty string.
mode	Ignored, operation mode.
acc	Ignored, should be zero.

Returns:: Pointer to a static NUTFILE structure.

References _NUTDEVICE::dev_dcb, _NUTFILE::nf_dev, _NUTFILE::nf_fcb, _NUTFILE::nf_next, and NULL.

int LpcDevDebugClose ( NUTFILE * fp )

Close debug device.

Parameters:

fp	Pointer to a _NUTFILE structure, obtained by a previous call to LpcDevDebugOpen().

Returns:: Always 0.

int LpcDevDebugIOCtl	(	NUTDEVICE *	dev,
		int	req,
		void *	conf
	)

Handle I/O controls for debug device 2.

The debug device supports UART_SETSPEED only.

Parameters:

dev	Identifies the device that receives the device-control function.
req	Requested control function. May be set to one of the following constants: UART_SETSPEED, conf points to an uint32_t value containing the baudrate.
conf	Points to a variable that contains any data required for the given control function or receives data from that function.

Returns:: 0 on success, -1 otherwise.

int LpcDevDebugWrite	(	NUTFILE *	fp,
		const void *	buffer,
		int	len
	)

Send characters to debug device 0.

This function is called by the low level input routines of the C runtime library, using the _NUTDEVICE::dev_write entry.

A newline character will be automatically prepended by a carriage return.

Parameters:

fp	Pointer to a _NUTFILE structure, obtained by a previous call to LpcDevDebugOpen().

Returns:: Number of characters sent.

References _NUTFILE::nf_dev.

Variable Documentation

NUTDEVICE devDebug0

Initial value:

 {
    NULL,               
    {'u', 'a', 'r', 't', '0', 0, 0, 0, 0}
    ,                   
    0,                  
    LPC_UART0_BASE,     
    0,                  
    NULL,               
    &dbg0file,          
    Debug0Init,         
    LpcDevDebugIOCtl,   



    NULL,               

    LpcDevDebugWrite,   
    LpcDevDebugOpen,    
    LpcDevDebugClose,   



    NULL                

}

Debug device 0 information structure.

Usually, the device structure is the only public symbol that may be referenced by the application code using

 #include <dev/debug.h>

 {
     ...
     NutRegisterDevice(&devDebug0, 0, 0);
     ...
 }

If not referenced, the driver code (and this structure) will not be included in the final binary.

The name of the structure may differ among platforms. Portable applications should avoid it and instead make use of dev/board.h.

 #include <dev/board.h>

 {
     ...
     NutRegisterDevice(&DEV_DEBUG, 0, 0);
     ...
 }

While output is supported by default, input may be not. If input is required, applications may replace DEV_DEBUG by DEV_CONSOLE. In this case the debug driver is selected only, if it has input capability (see NUT_DEV_DEBUG_READ). Otherwise an interrupt driven UART driver will be used.

Note, that this polling driver has certain advantages

very low memory usage
allows stdio output functions in interrupt context
allows stdio output functions in early system stage
no internal buffering, output is synchronous
atomic output with multiple threads

but also some disadvantages

concurrent threads are blocked during output
most or all UART settings are hard coded
may not work with non-ASCII (binary) data
often only output is supported, not input
only one instance (open) is allowed

When used with Harvard architectures, additional functions may be offered to access data in program space.

Functions

Variables

Function Documentation

Variable Documentation