ST7538-Q SPI Interface

[gobi123]

Hello people ,

we need some help from ST for solving the ST7538-Q interfacing with SPI .I don't even no where I have to ask the question .currently I am working in powerline communication using st7539-q and we are trying to communicate ST7538 -Q via SPI interface using this pins

RX( MOSI),

TX(MISO),

CLR/T(SCLK),

RxTx and REG_DATA for selecting the transmission (or) reception (or)control register read (or)control register write I can selecting using this pins (REG_DATA AND RxTx).....LIKE 00,01,10,11

TB= 417 Micro seconds

TCC=2*TB=834 Micro seconds

TCR=TB/4=104.25 Micro seconds

we are doing the as per the SPI clock diagram and and with this timing but we cant get nothing in the RX(MOSI)..Actually in datasheet they told if we do like SPI CLK DIAG we get some internal control register value but our mosi pin only on high nothing it will send.....

do you have a source code send it it will helpful for us

thank you



Plz give some response because we are struggling with in it .

 

[KlausST]

Hi,

RX( MOSI),

TX(MISO),

CLR/T(SCLK),

With SPI there is a SPI_Master (usually the Host controller) and a SPI_Slave.
Sadly you give no information about the SPI communication partner.
--> Please tell us about it.

Usually there is a microcontroller as Host controller and this is the SPI master.

But in your case it´s the other way round.
--> ST7538Q is always the SPI master (according datasheet)

--> Thus:
* Rx is an output (quite unusual naming)of the master, thus Master_output = MOSI
* Tx is an input (quite unusual naming)of the master, thus Master_input = MISO
* CLR/T is the spi SCK provided by the ST7538Q. The frequency is controlled with baud rate setup of the ST7538Q

* you need to configure the SPI partner to be a SPI_slave.

But I have to admit: The SPI interface is quite unusual and the documentation, too.

Klaus