ZedBoard UART 1 Rx

Not sure what 'low-echo' example you are referring to, but you might try either booting the Out of Box Linux or implementing the Zynq Concept Tools and Techniques tutorial for Zedboard to verify your hardware, Putty setup, and cabling are working for data transmission in both directions.

If your hardware setup works give us a few more details on the example you are trying to implement, your host OS, your Xilinx tool version, and if you are attempting a bare metal application.

-Gary

xuartps_low_echo_example is an example pointed to by my projects board support package for ps7_uart_1. This is running as a standalone application and putty is configured to 115200 baud, 8 data bits, 1 stop bit, and no parity or flow control. I also ran the self_test which configures UART 1 to loopback mode and it worked. xuartps_low_echo_example source follows.

#include "xparameters.h"
#include "xstatus.h"
#include "xil_types.h"
#include "xil_assert.h"
#include "xuartps_hw.h"

/************************** Constant Definitions ***************************/

/*
* The following constants map to the XPAR parameters created in the
* xparameters.h file. They are defined here such that a user can easily
* change all the needed parameters in one place.
*/
#define UART_BASEADDRttXPAR_XUARTPS_0_BASEADDR
#define UART_CLOCK_HZttXPAR_XUARTPS_0_CLOCK_HZ
/*
* The following constant controls the length of the buffers to be sent
* and received with the device. This constant must be 32 bytes or less so the
* entire buffer will fit into the TX and RX FIFOs of the device.
*/
#define TEST_BUFFER_SIZEt16

#define CHAR_ESCtt0x1bt/* 'ESC' character is used as terminator */

/**************************** Type Definitions *****************************/

/***************** Macros (Inline Functions) Definitions *******************/

/************************** Function Prototypes ****************************/

int UartPsEchoExample(u32 UartBaseAddress);

/************************** Variable Definitions ***************************/

/*
* The following buffers are used in this example to send and receive data
* with the UART.
*/
u8 SendBuffer[TEST_BUFFER_SIZE];t/* Buffer for Transmitting Data */


/***************************************************************************/
/**
*
* Main function to call the Uart Echo example.
*
* @paramtNone
*
* @returntXST_SUCCESS if successful, XST_FAILURE if unsuccessful
*
* @notettNone
*
****************************************************************************/
int main(void)
{
tint Status;

t/*
t * Run the Uart Echo example , specify the Base Address that is
t * generated in xparameters.h
t */
tStatus = UartPsEchoExample(UART_BASEADDR);
tif (Status != XST_SUCCESS) {
ttreturn XST_FAILURE;
t}

treturn XST_SUCCESS;
}


/**************************************************************************/
/**
*
* This function does a minimal test on the UART device using the hardware
* interface.
*
* @paramtUartBaseAddress is the base address of the device
*
* @returntXST_SUCCESS if successful, XST_FAILURE if unsuccessful
*
* @notettNone.
*
**************************************************************************/
int UartPsEchoExample(u32 UartBaseAddress)
{
tint Index;
tu32 Running;
tu8 RecvChar;
tu32 CntrlRegister;

tCntrlRegister = XUartPs_ReadReg(UartBaseAddress, XUARTPS_CR_OFFSET);

t/*
t * Enable TX and RX for the device
t */
tXUartPs_WriteReg(UartBaseAddress, XUARTPS_CR_OFFSET,
ttt  ((CntrlRegister & ~XUARTPS_CR_EN_DIS_MASK) |
ttt   XUARTPS_CR_TX_EN | XUARTPS_CR_RX_EN));
t/*
t * Initialize the send buffer bytes with a pattern to send and the
t * the receive buffer bytes to zero
t */
tfor (Index = 0; Index < TEST_BUFFER_SIZE; Index++) {
ttSendBuffer[Index] = Index + '0';
t}

t/*
t * Send the entire transmit buffer.
t */
tfor (Index = 0; Index < TEST_BUFFER_SIZE; Index++) {
tt/*
tt * Wait until there is space in TX FIFO
tt */
tt while (XUartPs_IsTransmitFull(UartBaseAddress));

tt/*
tt * Write the byte into the TX FIFO
tt */
ttXUartPs_WriteReg(UartBaseAddress, XUARTPS_FIFO_OFFSET,
tttt  SendBuffer[Index]);
t}

tRunning = TRUE;
twhile (Running) {
tt /*
tt  * Wait until there is data
tt  */
ttwhile (!XUartPs_IsReceiveData(UartBaseAddress));

ttRecvChar = XUartPs_ReadReg(UartBaseAddress,
ttttt    XUARTPS_FIFO_OFFSET);

tt/* Change the capitalization */
ttif (('a' <= RecvChar) && ('z' >= RecvChar)) {
ttt/* Convert the Capital letter to a small. */
tttRecvChar = RecvChar - 'a' + 'A';
tt}
ttelse if (('A' <= RecvChar) && ('Z' >= RecvChar)) {
ttt/* Convert the small letter to a Capital. */
tttRecvChar = RecvChar - 'A' + 'a';
tt}
ttelse if (CHAR_ESC == RecvChar) {
tttRunning = FALSE;
tt}

tt/* Echo the character back */
ttXUartPs_WriteReg(UartBaseAddress,  XUARTPS_FIFO_OFFSET,
tttt  RecvChar);
t}

treturn XST_SUCCESS;
}

I noticed that when running through the "set up debug" process under synthesis that UART1_RX was not included as a net, but UART0_RX was. Is this a Vivado bug? I selected UART 1 in the processing system block design.

Did you add the interrupt subsystem in hw block design? Did you never try the xuartps_intr_example.c in same folder?
V-italian

@myersar: for the sample code that you gave. Do we need FIFO in PL to store the values send through UART?

I mean how to get data from user to send though user!!

cin>>userinput;

SendBuffer[Index]=userinput;

Hi, I still have the same issue. It actually does not hangs on XUartPs_IsReceiveData(), but it just receve bad symbols. If you send the symbols at a different baud rate, they arrive (wrong symbols). This means that the HW is receiving things, but it is using a bad timing. I tested this with different baud rates and it is always the same.

Did you get to manage this issue?