DMA and Uart

for example i have to send this structure data do uart

typedef struct RS485{

float data1;

float data2;

int data3[10];

long data4;

}mydata;

with sizeof(mydata) i can know the lenght of datas to send

but there is not addressof(...) function to know the address in memory

of my data structure ;

The function alt_dma_txchan receive differents arguments , i can

put &mydata instead the address in memory , i will try

but where i specifie the uart ?

thanks

walter

ciao

i tryed different way .

In sopc builder connecting write port dma to ext bus ram

and read port dma to uart.

After setting flag end of packet for the uart

After without setting end of packet

i wrote following code :

# include "dma_test.h"

typedef struct COMM

{

float data1;

float data2;

float data3;

int data4;

int data5;

int data6;

int data7;

}Master;

Master data_send;

# define DMA_0_STATUS_REG 0# define DMA_0_READ_ADDR_REG 1# define DMA_0_WRITE_ADDR_REG 2# define DMA_0_LENGHT_REG 3 # define DMA_0_CONTROL_REG 6

int main(void)

{

data_send.data4=10;

data_send.data5=100;

data_send.data6=33;

data_send.data7=44;

IOWR(DMA_0_BASE,DMA_0_READ_ADDR_REG,&data_send);

IOWR(DMA_0_BASE,DMA_0_WRITE_ADDR_REG,UART_0_BASE);

IOWR(DMA_0_BASE,DMA_0_LENGHT_REG ,28);

IOWR(DMA_0_BASE,DMA_0_CONTROL_REG ,ALTERA_AVALON_DMA_CONTROL_BYTE_MSK | ALTERA_AVALON_DMA_CONTROL_GO_MSK | ALTERA_AVALON_DMA_CONTROL_WCON_MSK );

printf("data_send:%u\r ",sizeof(data_send));

while(true)

{

}

return(0);

}

i set fixed address for write port dma (uart) and else

but nothing was sent .

i can't understand what i need and what i have to do

Impossible to find good documentation for dma-uart , what to do in sopc builder

and what to do in sw.

Maybe need to set something for the uart ,but how

I need this to communicate different devices fpga in a new project but if i don't

know dma-uart i will make sending one byte at time , and load cpu for increasing buffer receive and transmiter .

Uncredible ..... not possible to find more informations about this

ciao

walter

better forget dma and nios II also

http://forum.niosforum.com/work2/style_emoticons/<#EMO_DIR#>/mad.gif

pmicro,

It should be possible to use a DMA to setup a streaming transfer from/to a block of memory... From what you&#39;ve mentioned, I believe you have a custom UART, so you should be aware that you do have to make sure that your UART supports streaming transactions.

BadOmen already pointed you to the resource on the DMA and there is a similar resource for the Avalon UART.

Please explain both your hardware and your software a bit better...and try to get simple memory-to-memory transfers working...first, with the DMA.

...and get an attitude improvement injection :-) This is, after all, a free forum!

Cheers,

- slacker

i&#39;m using stratix II development board .

I already complete my system with anything such as controller for ram , flash , ext flash , uart , niosII processor , my_timer ton , my_timer tof ,my_clocks ,

and dma

I saw a lot of documents , relative to avalon switch fabric , avalon bus , peripheral

slave , dma with hal , dma in reference handbook and for the uart too .

These documets only talk about streaming data beetwen memory to memoryThere are some code examples but relative to memory to memory not

uart and dma .I try different ways but nothing .

I try to use uart but indipendent, registering interrupt for empty register to send

and interrupt when receive a caracter .

But i don&#39;t want to use cpu and interrupt for communication , instead using dma ->uart and viceversa .

In sopc builder i connect master read port of dma to ram brodge slave port and

master write port of dma to uart fixed register .

I also set the flags in control register to heve this, you can see above but nothing .

I have , for example a structure data composed by different kind if data ,and

i get size of it using "sizeof(mydata_struct)" and then i pass &mydata_struct

like as address start for dma read source .

after that i pass uart0_base_address parameter for fixed address write source.

Of course setting relative bit in the control status dma_0.

Above you can see what i made in the sw , but i don&#39;t know if i have to

set something else .

Pratically i made nothing about the uart in the software , just set the

flag EOP end of packet , but this job is automatically make by avalon bus .

The dma controller use the EOP from uart to know when makes a new transaction to the uart .After dma transfer all data from memory , it give me an interrupt

and a flag in status register that it finish transaction.

With the cpu i have only to set regiaster flag and data for dma o also for the uart , if will be like this, how ?

There are not good explain to make this

http://forum.niosforum.com/work2/style_emoticons/<#EMO_DIR#>/blink.gif http://forum.niosforum.com/work2/style_emoticons/<#EMO_DIR#>/blink.gif http://forum.niosforum.com/work2/style_emoticons/<#EMO_DIR#>/blink.gif

Very strange , i am alone to use this tecnic .

thanks and regards

walter

in SOPC builder , for the uart there are only two flag to set

-RTS/DTS pins and control register bits

-Include end of packet register (for streaming data DMA control)

In my case they are setted both

Maybe i have to set only the second flag (steaming ....)

Tomorrow i will try , regenerate my system , update and download into fpga

good night

for BadOmen:

i already saw this document that you suggest to me

But uart doesn&#39;t run with Dma

Is one week that i&#39;m looking for documents about dma and uart but nothing

I cannot understand if is not possible or if is possible but difficult and need

more ingeneer to make this job

Very strange

ciao

walter

in sopc builder , dma and uart have some flags , but nothing else .

in IDE NIOS II i set flags to have dma operative , but what i have to do more ?

i cannot understand .

It&#39;s a very hard headache

ciao

walter