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UART Device
[Serial]

Collaboration diagram for UART Device:

Detailed Description

Device driver for ATmega On-Chip UART.

This device driver writes data to and reads data from the UART on the ATmega128/103 chip. Both, input and output data is buffered and send resp. transmitted by interrupt routines.

Not all ioctl() function are fully implemented. New applications should use the USART device driver.


Data Structures

struct  _UARTDCB
 UART device control block structure. More...
struct  _UARTDCB
 UART device control block structure. More...

Defines

#define UART_MF_RTSSENSE   0x00000001UL
#define UART_MF_CTSCONTROL   0x00000002UL
#define UART_MF_DTRSENSE   0x00000004UL
#define UART_MF_DSRCONTROL   0x00000008UL
#define UART_MF_DCDCONTROL   0x00000010UL
#define UART_MF_RTSCONTROL   0x00000020UL
#define UART_MF_CTSSENSE   0x00000040UL
#define UART_MF_DTRCONTROL   0x00000080UL
#define UART_MF_DSRSENSE   0x00000100UL
#define UART_MF_DCDSENSE   0x00000200UL
#define UART_MF_SENSEMASK   0x0345
#define UART_MF_CONTROLMASK   0x00BC
#define UART_MF_XONXOFF   0x00000400UL
#define UART_MF_LOCALECHO   0x00010000UL
#define UART_MF_COOKEDMODE   0x00020000UL
#define UART_MF_NOBUFFER   0x00100000UL
#define UART_MF_LINEBUFFER   0x00200000UL
#define UART_MF_BUFFERMASK   0x00300000UL
#define UART_MF_RAWMODE   0x00400000UL
#define UART_SF_RTSOFF   0x00000001UL
#define UART_SF_CTSOFF   0x00000002UL
#define UART_SF_DTROFF   0x00000004UL
#define UART_SF_DSROFF   0x00000008UL
#define UART_SF_DCDOFF   0x00000010UL
#define HDLC_SF_FLUSH   0x00001000UL
#define HDLC_SF_ESCAPED   0x00002000UL
#define UART_SF_TXDISABLED   0x00000040UL
#define UART_SF_RXDISABLED   0x00000080UL
#define UART_HS_DCERTSCTS   0x00000003UL
#define UART_HS_DCEFULL   0x0000001FUL
#define UART_HS_DTERTSCTS   0x00000060UL
#define UART_HS_DTEFULL   0x000003E0UL
#define UART_HS_XONXOFF   0x00000400UL

Typedefs

typedef _UARTDCB UARTDCB

Functions

int UartAvrInput (NUTDEVICE *dev)
 Wait for input.
int UartAvrOutput (NUTDEVICE *dev)
 Initiate output.
int UartAvrFlush (NUTDEVICE *dev)
 Wait for output buffer empty.
int UartAvrIOCtl (NUTDEVICE *dev, int req, void *conf)
 Perform on-chip UART control functions.
int UartAvrInit (NUTDEVICE *dev)
 Initialize on chip uart device.
int UartAvrRead (NUTFILE *fp, void *buffer, int size)
 Read from device.
int UartAvrPut (NUTDEVICE *dev, CONST void *buffer, int len, int pflg)
 Write to device.
int UartAvrWrite (NUTFILE *fp, CONST void *buffer, int len)
int UartAvrWrite_P (NUTFILE *fp, PGM_P buffer, int len)
NUTFILE * UartAvrOpen (NUTDEVICE *dev, CONST char *name, int mode, int acc)
 Open a device or file.
int UartAvrClose (NUTFILE *fp)
 Close a device or file.
long UartAvrSize (NUTFILE *fp)
 Request file size.

Variables

NUTDEVICE devUart0
 UART 0 Device information structure.
NUTDEVICE devUart1
 UART 1 Device information structure.

Define Documentation

#define UART_MF_RTSSENSE   0x00000001UL
 

DCE input, low on port bit is +12V, which means ON.

#define UART_MF_CTSCONTROL   0x00000002UL
 

DCE output.

#define UART_MF_DTRSENSE   0x00000004UL
 

DCE input.

#define UART_MF_DSRCONTROL   0x00000008UL
 

DCE output.

#define UART_MF_DCDCONTROL   0x00000010UL
 

DCE output.

#define UART_MF_RTSCONTROL   0x00000020UL
 

DTE output.

#define UART_MF_CTSSENSE   0x00000040UL
 

DTE input.

#define UART_MF_DTRCONTROL   0x00000080UL
 

DTE output.

#define UART_MF_DSRSENSE   0x00000100UL
 

DTE input.

#define UART_MF_DCDSENSE   0x00000200UL
 

DTE input.

#define UART_MF_SENSEMASK   0x0345
 

Handshake sense mask.

#define UART_MF_CONTROLMASK   0x00BC
 

Handshake control mask.

#define UART_MF_XONXOFF   0x00000400UL
 

Software handshake.

#define UART_MF_LOCALECHO   0x00010000UL
 

Should be used in stream, not device.

#define UART_MF_COOKEDMODE   0x00020000UL
 

Should be used in stream, not device.

#define UART_MF_NOBUFFER   0x00100000UL
 

No buffering.

#define UART_MF_LINEBUFFER   0x00200000UL
 

Line buffered.

#define UART_MF_BUFFERMASK   0x00300000UL
 

Masks buffering mode flags.

#define UART_MF_RAWMODE   0x00400000UL
 

Send data as raw, disables data encapsulation for device.

#define UART_SF_RTSOFF   0x00000001UL
 

Set RTS line is off.

#define UART_SF_CTSOFF   0x00000002UL
 

Set CTS line is off.

#define UART_SF_DTROFF   0x00000004UL
 

Set DTR line is off.

#define UART_SF_DSROFF   0x00000008UL
 

Set DSR line is off.

#define UART_SF_DCDOFF   0x00000010UL
 

Set DCD line is off.

#define HDLC_SF_FLUSH   0x00001000UL
 

Waiting for next HDLC flag.

#define HDLC_SF_ESCAPED   0x00002000UL
 

Next character escaped.

#define UART_SF_TXDISABLED   0x00000040UL
 

Transmitter disabled.

#define UART_SF_RXDISABLED   0x00000080UL
 

Receiver disabled.

#define UART_HS_DCERTSCTS   0x00000003UL
 

RTS/CTS DCE handshake.

#define UART_HS_DCEFULL   0x0000001FUL
 

Full DCE handshake.

#define UART_HS_DTERTSCTS   0x00000060UL
 

RTS/CTS DTE handshake.

#define UART_HS_DTEFULL   0x000003E0UL
 

Full DTE handshake.

#define UART_HS_XONXOFF   0x00000400UL
 

Software handshake.

Typedef Documentation

typedef struct _UARTDCB UARTDCB
 

UART device control block type.

Function Documentation

int UartAvrInput (  NUTDEVICE *  dev  ) 
 

Wait for input.

This function checks the input buffer for any data. If the buffer is empty, the calling thread will be blocked until at least one new character is received or a timeout occurs.

Parameters:
dev Indicates the UART device.
Returns:
0 on success, -1 on timeout.

int UartAvrOutput (  NUTDEVICE *  dev  ) 
 

Initiate output.

This function checks the output buffer for any data. If the buffer contains at least one character, the transmitter is started, if not already running. The function returns immediately, without waiting for the character being completely transmitted. Any remaining characters in the output buffer are transmitted in the background.

Parameters:
dev Indicates the UART device.
Returns:
0 on success, -1 otherwise.

int UartAvrFlush (  NUTDEVICE *  dev  ) 
 

Wait for output buffer empty.

If the output buffer contains any data, the calling thread is suspended until all data has been transmitted.

Parameters:
dev Indicates the UART device.
Returns:
0 on success, -1 otherwise.

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

Perform on-chip UART control functions.

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 u_long value containing the baudrate.
  • UART_GETSPEED, conf points to an u_long value receiving the current baudrate.
  • UART_SETDATABITS, conf points to an u_long value containing the number of data bits, 5, 6, 7 or 8.
  • UART_GETDATABITS, conf points to an u_long value receiving the number of data bits, 5, 6, 7 or 8.
  • UART_SETPARITY, conf points to an u_long value containing the parity, 0 (no), 1 (odd) or 2 (even).
  • UART_GETPARITY, conf points to an u_long value receiving the parity, 0 (no), 1 (odd) or 2 (even).
  • UART_SETSTOPBITS, conf points to an u_long value containing the number of stop bits 1 or 2.
  • UART_GETSTOPBITS, conf points to an u_long value receiving the number of stop bits 1 or 2.
  • UART_SETSTATUS
  • UART_GETSTATUS
  • UART_SETREADTIMEOUT, conf points to an u_long value containing the read timeout.
  • UART_GETREADTIMEOUT, conf points to an u_long value receiving the read timeout.
  • UART_SETWRITETIMEOUT, conf points to an u_long value containing the write timeout.
  • UART_GETWRITETIMEOUT, conf points to an u_long value receiving the write timeout.
  • UART_SETLOCALECHO, conf points to an u_long value containing 0 (off) or 1 (on).
  • UART_GETLOCALECHO, conf points to an u_long value receiving 0 (off) or 1 (on).
  • UART_SETFLOWCONTROL, conf points to an u_long value containing combined UART_FCTL_ values.
  • UART_GETFLOWCONTROL, conf points to an u_long value containing receiving UART_FCTL_ values.
  • UART_SETCOOKEDMODE, conf points to an u_long value containing 0 (off) or 1 (on).
  • UART_GETCOOKEDMODE, conf points to an u_long value receiving 0 (off) or 1 (on).
conf Points to a buffer that contains any data required for the given control function or receives data from that function.
Returns:
0 on success, -1 otherwise.
Warning:
Timeout values are given in milliseconds and are limited to the granularity of the system timer. To disable timeout, set the parameter to NUT_WAIT_INFINITE.
Note:
For ATmega103, only 8 data bits, 1 stop bit and no parity are allowed.

int UartAvrInit (  NUTDEVICE *  dev  ) 
 

Initialize on chip uart device.

Prepares the device for subsequent reading or writing. Enables UART transmitter and receiver interrupts.

Parameters:
dev Identifies the device to initialize.
Returns:
0 on success, -1 otherwise.

Variable Documentation

NUTDEVICE devUart0
 

Initial value:

 {
    0,                          
    {'u', 'a', 'r', 't', '0', 0, 0, 0, 0},      
    IFTYP_STREAM,               
    0,                          
    0,                          
    &ifs_uart0,                 
    &dcb_uart0,                 
    UartAvrInit,                
    UartAvrIOCtl,               
    UartAvrRead,                
    UartAvrWrite,               
    UartAvrWrite_P,             
    UartAvrOpen,                
    UartAvrClose,               
    UartAvrSize                 
}
UART 0 Device information structure.

NUTDEVICE devUart1
 

Initial value:

 {
    0,                          
    {'u', 'a', 'r', 't', '1', 0, 0, 0, 0},      
    IFTYP_STREAM,               
    1,                          
    0,                          
    &ifs_uart1,                 
    &dcb_uart1,                 
    UartAvrInit,                
    UartAvrIOCtl,               
    UartAvrRead,                                    
    UartAvrWrite,                                    
    UartAvrWrite_P,               
    UartAvrOpen,                               
    UartAvrClose,                             
    UartAvrSize                                    
}
UART 1 Device information structure.

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