uart hal questions ?

[Altera_Forum]

1. how can I open the uart for non blocking read ? 

2. how can I do "blocking output" with "non blocking read" ?  ( without modifying altera_avalon_uart.c) 3. how can I disable RTS/CTS in software ?    1. without OS a blocking uart read is not very usefull  I open the uart in the following way:  int fdterm; // FILEDESCRIPTOR RETURNED BY OPEN FILE *fpterm; // FILEPOINTER RETURNED BY FDOPEN   flags= O_RDWR | O_NONBLOCK | O_NOCTTY; fdterm = open(devicename,flags);  if(fdterm==0) {   DPRINTF("ERROR open devive:%s\r\n",devicename);  return -1; } fpterm=fdopen(fdterm,"rw+"); if(fpterm==0) {  DPRINTF("ERROR fdopen devive:%s\r\n",devicename); }  .. // then I can read nonblocking ... res=read(fdterm,uart1_tempbuff,sizeof(uart1_tempbuff)-1); if(res>0) {  // we have receuived any characters  .. }  2. using fprintf(fpterm,"...") I get scrambled output  I think this is because in "altera_avalon_uart.c" in function alt_avalon_uart_write the buffer is overwritten. I get  correct output, if I set disable "no_block=0" .. int alt_avalon_uart_write (alt_fd* fd, const char* ptr, int len) {  alt_irq_context context;  int no_block;  alt_u32 next;   alt_avalon_uart_dev* dev = (alt_avalon_uart_dev*) fd->dev;  int count = len;   /*   * Construct a flag to indicate whether the device is being accessed in  * blocking or non-blocking mode.  */   no_block = (fd->fd_flags & O_NONBLOCK);  no_block=0; // set no_block to 0 to get printf working   /* ...  3. I have configured the uart in sopc builder with RTS/CTS but don&#39;t want to use it in software. I use the following function to clear the flag ALT_AVALON_UART_FC.  ... int uart_set_flowcontrol(int filedescriptor,BYTE flowctrl) {    alt_fd* fd;   alt_avalon_uart_dev* dev; // pointer to uart device    if(filedescriptor<0) return -1;    // see alt_ioctrl.c  fd = (filedescriptor < 0) ? NULL : &alt_fd_list[filedescriptor];  if (fd) {  dev=(alt_avalon_uart_dev*)fd->dev;  if(flowctrl) {  dev->flags|=ALT_AVALON_UART_FC;  }  else {  dev->flags&=~ALT_AVALON_UART_FC;  }  return 0;  }     return -1;  } ...  4. I change baudrate with the function  ... int uart_set_baudrate(int filedescriptor,int baudrate) {  struct termios term;  int res;    res=ioctl(filedescriptor,TIOCMGET,&term);  if(res<0) {  DPRINTF("ERROR ioctl filedescriptor:%d\r\n",filedescriptor);  return res;  }  term.c_ispeed=baudrate;  term.c_ospeed=baudrate;  res=ioctl(filedescriptor,TIOCMSET,&term);  if(res<0) {  DPRINTF("ERROR ioctl filedescriptor:%d\r\n",filedescriptor);  }  return res;  } ...   is this correct ???

[Altera_Forum]

<div class='quotetop'>QUOTE </div> 

--- Quote Start ---  1. how can I open the uart for non blocking read ?[/b]  --- Quote End ---    As you put it in your example, this opens the UART non-blocking  int fdterm; // FILEDESCRIPTOR RETURNED BY OPEN  flags= O_RDWR | O_NONBLOCK | O_NOCTTY; fdterm = open(devicename,flags);   <div class='quotetop'>QUOTE </div>  --- Quote Start ---  2. how can I do "blocking output" with "non blocking read" ?[/b]  --- Quote End ---    Open it twice i.e.  int fdterm; // NON BLOCKING FILEDESCRIPTOR RETURNED BY OPEN int fdterm_block; // BLOCKING FILEDESCRIPTOR RETURNED BY OPEN  flags= O_RDWR | O_NONBLOCK | O_NOCTTY; fdterm = open(devicename,flags);   flags= O_RDWR | O_NOCTTY; fdterm_block = open(devicename,flags);   Use the appropriate handle depending upon whether you want blocking or non-blocking behaviour  <div class='quotetop'>QUOTE </div>  --- Quote Start ---  3. how can I disable RTS/CTS in software ?[/b]  --- Quote End ---   You can&#39;t it&#39;s asssumed that if you selected this hardware in SOPC Builder you will want the software. If you don&#39;t want RTS CTS turn it off in SOPC builder and save yourself some hardware resources

[Altera_Forum]

thanks rugbybloke, 

 the question of RTS/CTS is just that I don&#39;t know, if I will  need it later. Also I have 3 nearly equal projects, so that I don&#39;t want to change the sopc system. So I think, it only needs to clear the flag ALT_AVALON_UART_FC. Is the function "uart_set_flowcontrol correct" ???

[Altera_Forum]

The function looks OK to me, but try it.

[Altera_Forum]

Hi, 

 I can&#39;t seem to get the &#39;open&#39; command to work, only the &#39;fopen&#39; one which doesn&#39;t seem to support non-blocking access. What include files are you using?  Thanks,  Richard

[Altera_Forum]

The best way to find things like this is to use man on a unix machine, or type "linux man open" into google.

[Altera_Forum]

i think open is in <fcntl.h>, don&#39;t know if you need all, just a copy from my file 

# include <sys/ioctl.h> // open ???# include <fcntl.h># include<string.h> // rand(),srand()# include<stdlib.h> // write(),read(),usleep()# include<unistd.h> # include <priv/alt_file.h># include "altera_avalon_uart_regs.h"# include "altera_avalon_uart.h" # include<time.h>