TL16CP754C Example Drive Source Code in C

We do not have full sample source code available. I am working on some basic initialization and TX / RX handling code to provide to you. I hope to have it ready this afternoon.

Best Regards,

Joe

Hi Joe -

I am porting a driver written for the ST16C554 to the TL17C754.  The datasheet for the TL17C754 says it is pin compatible with the ST16C554.  When I compare the two datasheets it appears that they are software compatible as well.  Can you confirm?

Thanks,

Dan

Hi Joe

I am also using TL16C754C in my design and need the linux driver, will it be available from TI or Need to port taking reference from some other driver like the link you have provided above.

Regards

Vivek

Hello Vivek, 

Since UART driver support is provided with all of the major OSes we have not developed any sample code. There is some good sample code available through http://www.gnu.org. (https://ccrma.stanford.edu/courses/250a-fall-2002/docs/avrlib/uart_8c-source.html).

Best Regards,

Joe

Hi Joe,

I am able to make the initial version of driver and able to send data through the port one the chip, but not able to recieive and also not getting any interrupts on recieve, I am suspecting my basic register initialization sequence at start, it would be a great help if you have and send me the basic initialization sequence.

Thanks and Regards,

Vivek 

Hello Vivek,

Below is the basic initialization code used in most of our bench testing. 

Best Regards,

Joe

/******    TL16C754C Register Initialization Test Program    *****/

/*                                 */

/* Texas Instruments, Inc., 02-20-06                   */

/* Use 754C device on the 754CPM evaluation board.                    */

/* This program assumes a device is in socket, and address            */

/*   decode is set to x300-ChanA, x308-ChanB, x310-ChanC, x318-ChanD  */

/* This pgm sets up basic UART functionality with divisor = 11,       */

/*   all interrupts enabled, fifos enabled, and flow control disabled */

/*                  */

#include <dos.h>

#include <stdio.h>

#include <conio.h>

#include <stdlib.h>

#include <string.h>

#include <time.h>

/* Comm Port 1 or A -- UART register set definition */

#define RBR_UART1      0x300  /*Receiver Buffer Register of chA */

#define THR_UART1      0x300  /*Transmitter Holding Register of chA */

#define IER_UART1      0x301  /*Interrupt Enable Register of chA */

#define IIR_UART1      0x302  /*Interrupt Identify Register of chA */

#define FCR_UART1      0x302  /*FIFO Control Register of chA */

#define LCR_UART1      0x303  /*Line Control Register of chA */

#define MCR_UART1      0x304  /*Modem Control Register of chA */

#define LSR_UART1      0x305  /*Line Status Register of chA */

#define MSR_UART1      0x306  /*Modem Status Register of chA*/

#define SPR_UART1      0x307  /*Scratch Pad Register of chA */

#define DLL_UART1      0x300  /*Divisor Latch LSB of chA */

#define DLM_UART1      0x301  /*Divisor Latch MSB of chA */

/* End Comm Port definition */

/* Comm Port 2 or B -- UART register set definition */

#define RBR_UART2      0x308  /*Receiver Buffer Register of chB */

#define THR_UART2      0x308  /*Transmitter Holding Register of chB */

#define IER_UART2      0x309  /*Interrupt Enable Register of chB */

#define IIR_UART2      0x30A  /*Interrupt Identify Register of chB */

#define FCR_UART2      0x30A  /*FIFO Control Register of chB */

#define LCR_UART2      0x30B  /*Line Control Register of chB */

#define MCR_UART2      0x30C  /*Modem Control Register of chB */

#define LSR_UART2      0x30D  /*Line Status Register of chB */

#define MSR_UART2      0x30E  /*Modem Status Register of chB*/

#define SPR_UART2      0x30F  /*Scratch Pad Register of chB */

#define DLL_UART2      0x308  /*Divisor Latch LSB of chB */

#define DLM_UART2      0x309  /*Divisor Latch MSB of chB */

/* End Comm Port definition */

/* Comm Port 3 or C -- UART register set definition */

#define RBR_UART3      0x310  /*Receiver Buffer Register of chA */

#define THR_UART3      0x310  /*Transmitter Holding Register of chA */

#define IER_UART3      0x311  /*Interrupt Enable Register of chA */

#define IIR_UART3      0x312  /*Interrupt Identify Register of chA */

#define FCR_UART3      0x312  /*FIFO Control Register of chA */

#define LCR_UART3      0x313  /*Line Control Register of chA */

#define MCR_UART3      0x314  /*Modem Control Register of chA */

#define LSR_UART3      0x315  /*Line Status Register of chA */

#define MSR_UART3      0x316  /*Modem Status Register of chA*/

#define SPR_UART3      0x317  /*Scratch Pad Register of chA */

#define DLL_UART3      0x310  /*Divisor Latch LSB of chA */

#define DLM_UART3      0x311  /*Divisor Latch MSB of chA */

/* End Comm Port definition */

/* Comm Port 4 or D -- UART register set definition */

#define RBR_UART4      0x318  /*Receiver Buffer Register of chB */

#define THR_UART4      0x318  /*Transmitter Holding Register of chB */

#define IER_UART4      0x319  /*Interrupt Enable Register of chB */

#define IIR_UART4      0x31A  /*Interrupt Identify Register of chB */

#define FCR_UART4      0x31A  /*FIFO Control Register of chB */

#define LCR_UART4      0x31B  /*Line Control Register of chB */

#define MCR_UART4      0x31C  /*Modem Control Register of chB */

#define LSR_UART4      0x31D  /*Line Status Register of chB */

#define MSR_UART4      0x31E  /*Modem Status Register of chB*/

#define SPR_UART4      0x31F  /*Scratch Pad Register of chB */

#define DLL_UART4      0x318  /*Divisor Latch LSB of chB */

#define DLM_UART4      0x319  /*Divisor Latch MSB of chB */

/* End Comm Port definition */

// useful status defines for interrupt checking

#define recv_lin_stat    0xC6   /* FIFO enabled, receiver line status error*/

#define recv_data_avail  0xC4   /* Trigger lever reached */

#define char_time_out    0xCC   /* Character time_out */

#define xmt_thr_empty    0xC2   /* Transmitter Holding Register Empty */

main(

// setup ports (same ol' stuff)

/* Port 1 - Channel A */

outportb(LCR_UART1, 0x80);     /* Enable divisor access */

outportb(DLL_UART1, 0x0b;      /* set divisor           */

outportb(DLM_UART1, 0x00);

outportb(LCR_UART1, 0x03);     /* Set 8,N,1 data        */

outportb(FCR_UART1, 0xC7);     /* Enable and clear FIFOs, Rcv thresh=60  */     

outportb(IER_UART1, 0x0F);     /* Enable all interrupts */

outportb(MCR_UART1, 0x00);     /* Disable flow control   */

/* Port 2 - Channel B */

outportb(LCR_UART2, 0x80);     /* Enable divisor access */

outportb(DLL_UART2, 0x0b);     /* set divisor           */

outportb(DLM_UART2, 0x00);

outportb(LCR_UART2, 0x03);     /* Set 8,N,1 data */

outportb(FCR_UART2, 0xC7);     /* Enable and clear FIFOs, Rcv thresh=60  */ 

outportb(IER_UART2, 0x0F);     /* Enable all ints */

outportb(MCR_UART2, 0x00);     /* Disable flow control   */

/* Port 3 - Channel C */

outportb(LCR_UART3, 0x80);     /* Enable divisor access */

outportb(DLL_UART3, 0x0b;      /* set divisor           */

outportb(DLM_UART3, 0x00);

outportb(LCR_UART3, 0x03);     /* Set 8,N,1 data        */

outportb(FCR_UART3, 0xC7);     /* Enable and clear FIFOs, Rcv thresh=60  */     

outportb(IER_UART3, 0x0F);     /* Enable all interrupts */

outportb(MCR_UART3, 0x00);     /* Disable flow control   */

/* Port 4 - Channel D */

outportb(LCR_UART4, 0x80);     /* Enable divisor access */

outportb(DLL_UART4, 0x0b);     /* set divisor           */

outportb(DLM_UART4, 0x00);

outportb(LCR_UART4, 0x03);     /* Set 8,N,1 data */

outportb(FCR_UART4, 0xC7);     /* Enable and clear FIFOs, Rcv thresh=60  */ 

outportb(IER_UART4, 0x0F);     /* Enable all ints */

outportb(MCR_UART4, 0x00);     /* Disable flow control   */

void display_port_status()

{

     printf("UART1 Register Set value:\n");

     printf("IER = %x", inportb(IER_UART1) );

     printf("    LCR = %x", inportb(LCR_UART1) );

     printf("    MCR = %x", inportb(MCR_UART1) );

     printf("    LSR = %x", inportb(LSR_UART1) );

     printf("    MSR = %x", inportb(MSR_UART1) );

     printf("    IIR = %x\n", inportb(IIR_UART1) );

}  /* end of display_port_status */

}

/* end of main */

I used your mentioned values to initialize the UART:
LCR 0x80 - Enable divisor access
DLL 0x0c - set divisor to 12
DLH 0x00
LCR 0x03 - 8Bit, no Parity, 1 Stop
FCR 0xc7 - Enable and clear FIFO, Rcv thresh=60  
IER 0x0f - Enable all interrupts
MCR 0x00 - Disable flow control

when I read form LSR after initializing the UART I get 0x60 ("TSR and THR empty, THR empty"), which seems fine

Then I'm writing a Byte into THR and read the LSR again - now I get 0x40 ("TSR and THR empty, THR not empty") which seems quite contradictory as the THR can't be empty and filled at the same time.

And as Software and Hardware-Flowcontrol is disabled I'm expecting the UART to send the Byte on the Tx-Pin but it stays on High-Level all the time

Hello Joe,

I'm using the TL16CP754CI (64-Pin).

I tried your suggestion to store the initial LCR value and write it back after initializing the device but it didn't change anything for me:

Initialize the device, Read LSR -> 0x60, Write a Byte to THR, Read LSR again -> 0x40 and no action on the TX-Pin.

I noticed the pseudocode on page 44 already, but wouldn't I overwrite the Settings for 8Bit, No Parity, 1 Stop if I re-write the stored value into LCR?

Best Regards,

Andre

Hello Joe,

my power-up values in the registers are the same as yours, except the one in the scratch register, which is changing on every power-up but it keeps the value on reset.

And I still think writing a 0x1d into LCR would enable the "6bit, odd partiy, 2 stop" mode?

Best Regards,

Andre

dear sir,

we are using the TL16C754B in our application, can please provide us the application code for us.

by the way we can the code to our application.

regards,

srikanth.

Srikanth,

There is some general dual UART source code available from Stanford University at: https://ccrma.stanford.edu/courses/250a-fall-2003/docs/avrlib-new/uart2_8h.html

Best Regards,

Joe

Hey Joe,

I am a noob in device drivers. I was going through the Register Initialization Test Program. I would like to know what/how do you compile these programs and run it. I am using a proprietary board which is having Windows XP Embedded OS. I would like to know how this is done exactly. I came across this post when i was trying to write a sample program to see if i could access the device i/o address by writing and reading some data into it.

Anticipating positive early reply.

Thanks

Sudhir

Hi Friends,

I am also facing the same problem. I am Using tl16c752c dual uart . Initialization i followed the same but the LCR value when i read for the first time it is 0x60 .

I am getting LSR value as 40 . I am trying to write value to THR (0xaa) but the pin is always staying high. Please give me some guidance in this regard.

My register values are as follows

DLL ->0x9

DLH -> 0x0

LCR -> 0x3

FCR -> 0xC7

IER -> 0xF

MCR -> 0

LSR -> 0x40

thanks in advance

Saritha

Joe Fockler said:

Because the applications for UART or so varied we do not have specific source code. Attached is some general initialization code for setting up a UART to begin transmitting and receiving. We do not have a software team that can provide support.or detailed source code.

Hello Joe,

Is it possible to share schematic for 754CPM evaluation board for which the test program was made

best regards,

Oleksiy

Hello Oleksiy,

Sure. Please see attached schematics.

Best Regards,

Joe