On Monday 06 July 2009 11:55:11 pouettagada wrote:
> In fact, I'd like to use the SSP as a SPI bus.
I've found appnote with
> example to use the SPI bus, but not with the pins that I use. appnote use
> the SPI interface and I'd like to use the SSP as a SPI... (pins
> P0.17,18,19,20 )
>
> How can I do it? Where can I found a full datasheet? I'm affraid that
this
> information is not in the datasheet from NXP/Philips (no information how to
> configure ssp as spi, not information about registers to read value....)
>
> I think I have just a "light" version of the datasheet
Could be that you're reading the wrong document; NXP has datasheets (short
feature list, ~40 pages or so) and user manuals (~300 pages or so).
The latter is what you need. It does contains all SSP registers, and how to
use them.
Regards,
-Bastiaan
How to access to the SPI bus (LPC2138)
Started by ●July 3, 2009
Reply by ●July 6, 20092009-07-06
Reply by ●July 6, 20092009-07-06
i am working on LPC 2148.
i am pasting the code whatever i have done.
/*FOLLOWING CODE IS THE MASTER CODE*/
#include "LPC2148.h"
#include "UART0.h"
#include "pll.h"
#include
void SPI_Init(void)
{
Tx_string("I am in INITIALIZATION part\n");
IO0DIR |=0x00000080; //(SSEL) pin p0.7 is used as output to select the
slave(herae slave is another LPC 2148 board)
IO0CLR=0x00000080; //before the transfer of data and during the data
transfer (SSEL) P0.7 made it LOW.
PINSEL0 |= 0x00001505; //selecting the pins for transmitter and
receiver,SCK0,MISO and MOSI except SSEL
S0SPCCR = 0x0C; //clock rate for SPI bus 12MHZ/12 =1 MHZ.
Tx_string("I am in middle of INITIALIZATION part\n");
S0SPCR = 0xA8; // CPHA=1, CPOL=0, master mode, MSB first, interrupt enabled
Tx_string("I am in ending of INITIALIZATION part\n");
Tx_string("I am in ending 12 of INITIALIZATION part\n");
}
WORD32 SPI_SendAndReceive (WORD32 value)
{
WORD32 value1;
S0SPDR = value ; //Writing the data in to the data register
while(!(S0SPSR&0x80)) ; //waiting for SPIF bit be one to indicate the
transfer complete
value1 = S0SPSR ;// read and ignore status
return S0SPDR;
}
int main(void)
{
PLL_init(); //initialization of PLL, i am using 12 MZ only,PLL settings not
necessary here.
InitUart0(); //initialization of UART0,i am using 9600 baud rate.
Tx_string("I AM IN START OF MASTER\n");
SPI_Init(); // initilization of SPI BUS
Tx_string("INITIALIZATION IS OVER\n");
while(1)
{
WORD32 temp, temp2 ;
Tx_string("Press any key to transmit it's ASCII code to SPI.\n") ;
temp = Rx_char();
temp2 = SPI_SendAndReceive(temp) ;
printf("Sent 0x%02X to SPI, sen to 0x%02X to SPI \n\n", temp,temp2) ;
}
}
here Tx_String is the function to display the string on the hyperterminal is
defined in UART code.
/*FOLLOWING CODE is the UART code*/
#include "LPC2148.h"
#define DESIRED_BAUDRATE 9600
#define CRYSTAL_FREQUENCY_IN_HZ 12000000
#define PCLK CRYSTAL_FREQUENCY_IN_HZ
#define DIVISOR (PCLK/(16*DESIRED_BAUDRATE))
void InitUart0(void)
{
/* U0LCR: UART0 Line Control Register
0x83: enable Divisor Latch access, set 8-bit word length,
1 stop bit, no parity, disable break transmission */
U0LCR=0x83;
/* VPBDIV: VPB bus clock divider
0x01: PCLK = processor clock */
VPBDIV=0x01;
/* U0DLL: UART0 Divisor Latch (LSB) */
U0DLL=DIVISOR&0xFF;
/* U0DLM: UART0 Divisor Latch (MSB) */
U0DLM=DIVISOR>>8;
/* U0LCR: UART0 Line Control Register
0x03: same as above, but disable Divisor Latch access */
U0LCR=0x03 ;
/* U0FCR: UART0 FIFO Control Register
0x05: Clear Tx FIFO and enable Rx and Tx FIFOs */
U0FCR=0x05 ;
}
char Tx_char(char ch)
{
if (ch=='\n')
{
//wait until Transmit Holding Register is empty
while (!(U0LSR&0x20)) {}
//then store to Transmit Holding Register
U0THR='\r';
}
//wait until Transmit Holding Register is empty
while (!(U0LSR&0x20)) {}
//then store to Transmit Holding Register
U0THR=ch;
return ch;
}
char Rx_char(void)
{
char ch;
//wait until there's a character to be read
while (!(U0LSR&0x01)) {}
//then read from the Receiver Buffer Register
ch=U0RBR;
return ch;
}
int IsUart0Ready ()
{
// returns non-zero if a char is received on UART0
return(U0LSR & 0x01) ;
}
int Tx_string(char *s)
{
int i=0;
while(s[i]!='\0')
{
Tx_char(s[i]);
i++;
}
return(i);
}
/*following code is the PLL CODE*/
#include "LPC2148.h" /* LPC21xx definitions */
//#include "type.h"
#include "pll.h"
/*****************************
************************************************
PLL initialization function
****************************************************************************/
void PLL_init (void)
{
PLLCFG=0x00000060; // set multiplier and divider of PLL to give 12.00 MHz
PLLCON= 0x00000001; // enable PLL
PLLFEED= 0x000000AA; // update PLL registers with feed sequence
PLLFEED= 0x00000055;
while(!(PLLSTAT & 0x00000400)); // test lock bit
PLLCON= 0x00000003; // connect the PLL
PLLFEED= 0x000000AA; // update PLL registers with feed sequence
PLLFEED= 0x00000055;
VPBDIV = 0x00000001; // set the VLSI perpheral bus to 12.00 MHz
}
/*****************************************************************************
End Of File
*****************************************************************************/
In Master program,temp varable value is displaying hyperterminal but temp2
value is not displaying.it is displaying 0x00 whatever i am entered.So
whatever i am entering,it is not storing in to the S0SPDR and i am not able
to read the S0SPDR once transfer is completed.
PLZ help me,thanks in advance to all
On Mon, Jul 6, 2009 at 3:58 PM, Bastiaan van Kesteren
wrote:
> On Monday 06 July 2009 11:55:11 pouettagada wrote:
> > In fact, I'd like to use the SSP as a SPI bus. I've found appnote with
> > example to use the SPI bus, but not with the pins that I use. appnote use
> > the SPI interface and I'd like to use the SSP as a SPI... (pins
> > P0.17,18,19,20 )
> >
> > How can I do it? Where can I found a full datasheet? I'm affraid that
> this
> > information is not in the datasheet from NXP/Philips (no information how
> to
> > configure ssp as spi, not information about registers to read value....)
> >
> > I think I have just a "light" version of the datasheet
>
> Could be that you're reading the wrong document; NXP has datasheets (short
> feature list, ~40 pages or so) and user manuals (~300 pages or so).
>
> The latter is what you need. It does contains all SSP registers, and how to
> use them.
>
> Regards,
> -Bastiaan
>
i am pasting the code whatever i have done.
/*FOLLOWING CODE IS THE MASTER CODE*/
#include "LPC2148.h"
#include "UART0.h"
#include "pll.h"
#include
void SPI_Init(void)
{
Tx_string("I am in INITIALIZATION part\n");
IO0DIR |=0x00000080; //(SSEL) pin p0.7 is used as output to select the
slave(herae slave is another LPC 2148 board)
IO0CLR=0x00000080; //before the transfer of data and during the data
transfer (SSEL) P0.7 made it LOW.
PINSEL0 |= 0x00001505; //selecting the pins for transmitter and
receiver,SCK0,MISO and MOSI except SSEL
S0SPCCR = 0x0C; //clock rate for SPI bus 12MHZ/12 =1 MHZ.
Tx_string("I am in middle of INITIALIZATION part\n");
S0SPCR = 0xA8; // CPHA=1, CPOL=0, master mode, MSB first, interrupt enabled
Tx_string("I am in ending of INITIALIZATION part\n");
Tx_string("I am in ending 12 of INITIALIZATION part\n");
}
WORD32 SPI_SendAndReceive (WORD32 value)
{
WORD32 value1;
S0SPDR = value ; //Writing the data in to the data register
while(!(S0SPSR&0x80)) ; //waiting for SPIF bit be one to indicate the
transfer complete
value1 = S0SPSR ;// read and ignore status
return S0SPDR;
}
int main(void)
{
PLL_init(); //initialization of PLL, i am using 12 MZ only,PLL settings not
necessary here.
InitUart0(); //initialization of UART0,i am using 9600 baud rate.
Tx_string("I AM IN START OF MASTER\n");
SPI_Init(); // initilization of SPI BUS
Tx_string("INITIALIZATION IS OVER\n");
while(1)
{
WORD32 temp, temp2 ;
Tx_string("Press any key to transmit it's ASCII code to SPI.\n") ;
temp = Rx_char();
temp2 = SPI_SendAndReceive(temp) ;
printf("Sent 0x%02X to SPI, sen to 0x%02X to SPI \n\n", temp,temp2) ;
}
}
here Tx_String is the function to display the string on the hyperterminal is
defined in UART code.
/*FOLLOWING CODE is the UART code*/
#include "LPC2148.h"
#define DESIRED_BAUDRATE 9600
#define CRYSTAL_FREQUENCY_IN_HZ 12000000
#define PCLK CRYSTAL_FREQUENCY_IN_HZ
#define DIVISOR (PCLK/(16*DESIRED_BAUDRATE))
void InitUart0(void)
{
/* U0LCR: UART0 Line Control Register
0x83: enable Divisor Latch access, set 8-bit word length,
1 stop bit, no parity, disable break transmission */
U0LCR=0x83;
/* VPBDIV: VPB bus clock divider
0x01: PCLK = processor clock */
VPBDIV=0x01;
/* U0DLL: UART0 Divisor Latch (LSB) */
U0DLL=DIVISOR&0xFF;
/* U0DLM: UART0 Divisor Latch (MSB) */
U0DLM=DIVISOR>>8;
/* U0LCR: UART0 Line Control Register
0x03: same as above, but disable Divisor Latch access */
U0LCR=0x03 ;
/* U0FCR: UART0 FIFO Control Register
0x05: Clear Tx FIFO and enable Rx and Tx FIFOs */
U0FCR=0x05 ;
}
char Tx_char(char ch)
{
if (ch=='\n')
{
//wait until Transmit Holding Register is empty
while (!(U0LSR&0x20)) {}
//then store to Transmit Holding Register
U0THR='\r';
}
//wait until Transmit Holding Register is empty
while (!(U0LSR&0x20)) {}
//then store to Transmit Holding Register
U0THR=ch;
return ch;
}
char Rx_char(void)
{
char ch;
//wait until there's a character to be read
while (!(U0LSR&0x01)) {}
//then read from the Receiver Buffer Register
ch=U0RBR;
return ch;
}
int IsUart0Ready ()
{
// returns non-zero if a char is received on UART0
return(U0LSR & 0x01) ;
}
int Tx_string(char *s)
{
int i=0;
while(s[i]!='\0')
{
Tx_char(s[i]);
i++;
}
return(i);
}
/*following code is the PLL CODE*/
#include "LPC2148.h" /* LPC21xx definitions */
//#include "type.h"
#include "pll.h"
/*****************************
************************************************
PLL initialization function
****************************************************************************/
void PLL_init (void)
{
PLLCFG=0x00000060; // set multiplier and divider of PLL to give 12.00 MHz
PLLCON= 0x00000001; // enable PLL
PLLFEED= 0x000000AA; // update PLL registers with feed sequence
PLLFEED= 0x00000055;
while(!(PLLSTAT & 0x00000400)); // test lock bit
PLLCON= 0x00000003; // connect the PLL
PLLFEED= 0x000000AA; // update PLL registers with feed sequence
PLLFEED= 0x00000055;
VPBDIV = 0x00000001; // set the VLSI perpheral bus to 12.00 MHz
}
/*****************************************************************************
End Of File
*****************************************************************************/
In Master program,temp varable value is displaying hyperterminal but temp2
value is not displaying.it is displaying 0x00 whatever i am entered.So
whatever i am entering,it is not storing in to the S0SPDR and i am not able
to read the S0SPDR once transfer is completed.
PLZ help me,thanks in advance to all
On Mon, Jul 6, 2009 at 3:58 PM, Bastiaan van Kesteren
wrote:
> On Monday 06 July 2009 11:55:11 pouettagada wrote:
> > In fact, I'd like to use the SSP as a SPI bus. I've found appnote with
> > example to use the SPI bus, but not with the pins that I use. appnote use
> > the SPI interface and I'd like to use the SSP as a SPI... (pins
> > P0.17,18,19,20 )
> >
> > How can I do it? Where can I found a full datasheet? I'm affraid that
> this
> > information is not in the datasheet from NXP/Philips (no information how
> to
> > configure ssp as spi, not information about registers to read value....)
> >
> > I think I have just a "light" version of the datasheet
>
> Could be that you're reading the wrong document; NXP has datasheets (short
> feature list, ~40 pages or so) and user manuals (~300 pages or so).
>
> The latter is what you need. It does contains all SSP registers, and how to
> use them.
>
> Regards,
> -Bastiaan
>
Reply by ●July 6, 20092009-07-06
--- In l..., "raju_nem" wrote:
>
> the output of following pasted code is given below.
> Press any key to transmit it's ASCII code to SPI.
> Sent 0x61 to SPI, sen to 0x00 to SPI
>
> Press any key to transmit it's ASCII code to SPI.
> Sent 0x62 to SPI, sen to 0x00 to SPI
>
> Press any key to transmit it's ASCII code to SPI.
> Sent 0x63 to SPI, sen to 0x00 to SPI
> Just look at closely.first i entered character a,it is displayed 0x61
> ,but value of temp2 after storing the data ,is not displaying as 0x61
> but here it is displaying the 0x00.Hence i conclude that,whatever i am
> storing the data in to S0SPDR is not storing and iam not able to read
> the data from SOSPDR.
Your SPI is set up for 8 bit transfers and, at most, can do 16 bit transfers. Be certain that the data you send is the proper byte of the 32 bit word.
How are you getting your data back into the SPI gadget? Do you have a loop between MOSI and MISO? Otherwise, MOSI sends the bits out and MISO gets nothing back in. BTW, I'm not sure a loop (wire) will work. I'd have to think about the clocking. Is the data presented before the clock in sufficient time to be able to grab it back in on MISO?
The setup looks ok. Are you getting SCK and MOSI signals? Have you looked with a scope?
Richard
>
> the output of following pasted code is given below.
> Press any key to transmit it's ASCII code to SPI.
> Sent 0x61 to SPI, sen to 0x00 to SPI
>
> Press any key to transmit it's ASCII code to SPI.
> Sent 0x62 to SPI, sen to 0x00 to SPI
>
> Press any key to transmit it's ASCII code to SPI.
> Sent 0x63 to SPI, sen to 0x00 to SPI
> Just look at closely.first i entered character a,it is displayed 0x61
> ,but value of temp2 after storing the data ,is not displaying as 0x61
> but here it is displaying the 0x00.Hence i conclude that,whatever i am
> storing the data in to S0SPDR is not storing and iam not able to read
> the data from SOSPDR.
Your SPI is set up for 8 bit transfers and, at most, can do 16 bit transfers. Be certain that the data you send is the proper byte of the 32 bit word.
How are you getting your data back into the SPI gadget? Do you have a loop between MOSI and MISO? Otherwise, MOSI sends the bits out and MISO gets nothing back in. BTW, I'm not sure a loop (wire) will work. I'd have to think about the clocking. Is the data presented before the clock in sufficient time to be able to grab it back in on MISO?
The setup looks ok. Are you getting SCK and MOSI signals? Have you looked with a scope?
Richard
Reply by ●July 6, 20092009-07-06
Oh yes ok thanks a lot for your reply...
I download this book...
--- In l..., Bastiaan van Kesteren wrote:
>
> On Monday 06 July 2009 11:55:11 pouettagada wrote:
> > In fact, I'd like to use the SSP as a SPI bus. I've found appnote with
> > example to use the SPI bus, but not with the pins that I use. appnote use
> > the SPI interface and I'd like to use the SSP as a SPI... (pins
> > P0.17,18,19,20 )
> >
> > How can I do it? Where can I found a full datasheet? I'm affraid that this
> > information is not in the datasheet from NXP/Philips (no information how to
> > configure ssp as spi, not information about registers to read value....)
> >
> > I think I have just a "light" version of the datasheet
>
> Could be that you're reading the wrong document; NXP has datasheets (short
> feature list, ~40 pages or so) and user manuals (~300 pages or so).
>
> The latter is what you need. It does contains all SSP registers, and how to
> use them.
>
> Regards,
> -Bastiaan
>
I download this book...
--- In l..., Bastiaan van Kesteren wrote:
>
> On Monday 06 July 2009 11:55:11 pouettagada wrote:
> > In fact, I'd like to use the SSP as a SPI bus. I've found appnote with
> > example to use the SPI bus, but not with the pins that I use. appnote use
> > the SPI interface and I'd like to use the SSP as a SPI... (pins
> > P0.17,18,19,20 )
> >
> > How can I do it? Where can I found a full datasheet? I'm affraid that this
> > information is not in the datasheet from NXP/Philips (no information how to
> > configure ssp as spi, not information about registers to read value....)
> >
> > I think I have just a "light" version of the datasheet
>
> Could be that you're reading the wrong document; NXP has datasheets (short
> feature list, ~40 pages or so) and user manuals (~300 pages or so).
>
> The latter is what you need. It does contains all SSP registers, and how to
> use them.
>
> Regards,
> -Bastiaan
>
Reply by ●July 7, 20092009-07-07
Thank for u r reply
i am not getting the SCK signal on oscillioscope.
On Mon, Jul 6, 2009 at 7:06 PM, rtstofer wrote:
> --- In l... , "raju_nem"
> wrote:
> >
> > the output of following pasted code is given below.
> >
> >
> > Press any key to transmit it's ASCII code to SPI.
> > Sent 0x61 to SPI, sen to 0x00 to SPI
> >
> > Press any key to transmit it's ASCII code to SPI.
> > Sent 0x62 to SPI, sen to 0x00 to SPI
> >
> > Press any key to transmit it's ASCII code to SPI.
> > Sent 0x63 to SPI, sen to 0x00 to SPI
> >
> >
> > Just look at closely.first i entered character a,it is displayed 0x61
> > ,but value of temp2 after storing the data ,is not displaying as 0x61
> > but here it is displaying the 0x00.Hence i conclude that,whatever i am
> > storing the data in to S0SPDR is not storing and iam not able to read
> > the data from SOSPDR.
>
> Your SPI is set up for 8 bit transfers and, at most, can do 16 bit
> transfers. Be certain that the data you send is the proper byte of the 32
> bit word.
>
> How are you getting your data back into the SPI gadget? Do you have a loop
> between MOSI and MISO? Otherwise, MOSI sends the bits out and MISO gets
> nothing back in. BTW, I'm not sure a loop (wire) will work. I'd have to
> think about the clocking. Is the data presented before the clock in
> sufficient time to be able to grab it back in on MISO?
>
> The setup looks ok. Are you getting SCK and MOSI signals? Have you looked
> with a scope?
>
> Richard
>
>
>
--
Raju Nalla
Application Engineer
Unistring Tech solution pvt Ltd
i am not getting the SCK signal on oscillioscope.
On Mon, Jul 6, 2009 at 7:06 PM, rtstofer wrote:
> --- In l... , "raju_nem"
> wrote:
> >
> > the output of following pasted code is given below.
> >
> >
> > Press any key to transmit it's ASCII code to SPI.
> > Sent 0x61 to SPI, sen to 0x00 to SPI
> >
> > Press any key to transmit it's ASCII code to SPI.
> > Sent 0x62 to SPI, sen to 0x00 to SPI
> >
> > Press any key to transmit it's ASCII code to SPI.
> > Sent 0x63 to SPI, sen to 0x00 to SPI
> >
> >
> > Just look at closely.first i entered character a,it is displayed 0x61
> > ,but value of temp2 after storing the data ,is not displaying as 0x61
> > but here it is displaying the 0x00.Hence i conclude that,whatever i am
> > storing the data in to S0SPDR is not storing and iam not able to read
> > the data from SOSPDR.
>
> Your SPI is set up for 8 bit transfers and, at most, can do 16 bit
> transfers. Be certain that the data you send is the proper byte of the 32
> bit word.
>
> How are you getting your data back into the SPI gadget? Do you have a loop
> between MOSI and MISO? Otherwise, MOSI sends the bits out and MISO gets
> nothing back in. BTW, I'm not sure a loop (wire) will work. I'd have to
> think about the clocking. Is the data presented before the clock in
> sufficient time to be able to grab it back in on MISO?
>
> The setup looks ok. Are you getting SCK and MOSI signals? Have you looked
> with a scope?
>
> Richard
>
>
>
--
Raju Nalla
Application Engineer
Unistring Tech solution pvt Ltd
