MCU-PLUS-SDK-AM273X: SPI development

Hi Ming,

Thank you very much for your reply. And I'm glad you are responsible to my new post again.

What's the difference between mibspi and standard spi? Can I set mibspi to standard spi?

Also, I have import and built the sample project mibspi_loopback_r5fss0-0_nortos. Now I plan to modify the mibspi to connect with external device with standard spi. Set AM273x in master spi mode and assign physical pins to the EVM headers. How should I do them? 

I plan to start from .syscfg file. Is it a good way to start from? If yes, how should I do? Could you provide some detailed instructions with screenshots?

Appreciate your help and support.

Best regards,

Lin

Hi Ming,

Thanks for your instructions. I am working on the example.syscfg. I have two questions.

- Can I disable loopback mode in the example.syscfg? Or I can only do it in the code.

- For the Pin Assignment, the current setting is:

MIBSPI CLK Pin(MSS_MIBSPIA_CLK) PAD_DJ/G19 with Pull Up
MIBSPI MISO Pin(MSS_MIBSPIA_MISO) PAD_DI/G17 with Pull Up
MIBSPI MOSI Pin(MSS_MIBSPIA_MOSI) PAD_DH/H18 with Pull Up

CS Pin PAD_DK/F19 No Pull

How can I measure/test those 4 pins signals on the EVM board?

Best regards,

Lin

Hi Ming,

Could you point me to the EVM board schematics file?

Thanks,

Lin

Hi Ming,

Thanks for your help and links to the documents. I will study them and get back to you later.

Regards,

Lin

Hi Ming,

After carefully reading the EVM User Guide, especially the section 2.2.9 SPI Interface, I notice that there are four SPI choices:

- MSS_SPIA is wired to FTDI USB port (J10). However, I'm not sure how I can test the 4 pin signals of MSS_SPIA on J10.

- MSS_SPIB can be multiplexed and connected to J16 by setting S2 to PMIC_SPI position. Also the R5, R61, R167 and R176 need to be populated with 0 ohm (by checking the S2 part and BOM of EVM). Do you think MSS_SPIB to J16 is a good choice? If so, I need to add 4 resistors on the EVM board and modify the example.syscfg file to MSS_SPIB. Please give your comments.

- RCSS_SPIA routed to J1 (60 pin connector), it's hard to get the SPI signals.

- RCSS_SPIB routed to J11 (60 pin connector), it's hard to get the SPI signals.

Could you provide your advice before I go ahead further? If you could explain your choice, that would be great.

Best regards,

Lin

Hi Ming,

Do you mean you will use RCSS_SPIA or RCSS_SPIB and get signal from the 60-pin connector with the adapter? How about the MSS_SPIA or MSS_SPIB?

Thanks,
Lin

Hi Ming,

Oh, MSS_SPIB can be connected to J7 60-pin connector too. 

Could you describe your choice and setting in more detail?

Best regards,

Lin

Hi Ming,

Thanks. I didn't have that idea. Now clear.

If we choose MSS_SPIA, do we need to use the 60-pin breakout adapter (ZX100-QTH030-ST Samtec Breakout Adapter)? 

Regards,

Lin

Hi Ming,

Thanks for your explanation. Those are what I was leant from the User Guide, schematics and BOM files.

I will do more tests and get back to you later.

Best regards,

Lin

Hi Ming,

The EVM board has been modified to support MSS_SPIB on J16. Now I'm modifying the sample code to support MSS_SPIB and our slave device.

Here I have a question about code debugging and running.

After building the project by right clicking on the project name and choosing Build Project, how will you do to debug or run the project code? By right clicking project name and choosing Debug As / 1 Code Composer Debug Session ? or some other way?

Appreciate your sharing and advice.

Best regards,

Lin

Hi Ming,

As we plan to connect AM273x with multiple devices via SPI, I want to use GPIO pins as CS for different device.  Questions are as below.

- When I check the schematic of EVM board, the MSS_GPIO_2 is connected to LED D6. However, in the example.syscfg file the GPIO Pin(MSS_GPIO26). Do they match each other?  How should I choose the PAD numbers in the example.syscfg file?

- Where can I find some other GPIO pin test points on the EVM board?

Appreciate your help.

Best regards,

Lin

Hi Ming,

Thanks for your reply and GPIO pin information. I checked the Table 5-1 of datasheet and confirmed the info. However, once I choose those pins D19 and U17, How/Where can I get them on the EVM board?

Best regards,

Lin

Hi Ming,

Another question about MIBSPI setting in the example.syscfg file. What's the difference between Xbar Instance and SPI Instance? Should they be chosen the same value? now they are both the MSS_MIBSPIB / MSS_MIBSPIB or MSS_MIBSPIA / MSS_MIBSPIA.

Thanks,

Lin

Thanks Ming, I will keep the setting.

Regards,

Lin

Thanks Ming,

I will try to order the adapter and do more tests. Right now I'm working on 4 pin setting of MSS_SPIB connecting to J16. I will get back to you about the SPI testing and verifying.

Best regards,

Lin

Hi Ming,

When I modify the mibspi_loopback.c file, I have following part of code:

uint8_t const reg_addr = 0x1A;
uint16_t const reg_data = 0xAA55;

uint32_t lmx_frame = (0U << 23) | (reg_addr << 16) | reg_data; // 24-bit frame from LMX2595

uint16_t txBuf[2];
uint16_t rxBuf[2] = {0};

txBuf[0] = (lmx_frame >> 8) & 0xFFFF; // Upper 16 bits
txBuf[1] = (lmx_frame & 0xFF) << 8; // Lower 8 bits aligned to MSB

When I build the project, got following error and warning messages:

../mibspi_loopback.c:71:1: warning: type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int [-Wimplicit-int]
txBuf[0] = (lmx_frame >> 8) & 0xFFFF; // Upper 16 bits
^
int
../mibspi_loopback.c:71:1: error: redefinition of 'txBuf' with a different type: 'int[0]' vs 'uint16_t[2]' (aka 'unsigned short[2]')
../mibspi_loopback.c:68:10: note: previous definition is here
uint16_t txBuf[2];
^
../mibspi_loopback.c:72:1: warning: type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int [-Wimplicit-int]
txBuf[1] = (lmx_frame & 0xFF) << 8; // Lower 8 bits aligned to MSB
^
int
../mibspi_loopback.c:72:1: error: redefinition of 'txBuf' with a different type: 'int[1]' vs 'uint16_t[2]' (aka 'unsigned short[2]')
../mibspi_loopback.c:68:10: note: previous definition is here
uint16_t txBuf[2];
^

Do you have any hint and suggestion for those errors and warning? The screenshot is as below: (oh, sorry, seems I can't paste any screenshort here)

expecting for your reply.

Best regards,

Lin

Hi Ming,

Any suggestion I can fix the error the txBuf has been defined twice (line 71 and line 68). One as the int and the other is uint16_t. I tried many ways to type cast and the other methods, but not succeed.

As our connecting device needs 24-bit frame pattern, so I want to create the 2 16-bit data dynamically from the input register address and register data.

uint16_t txBuf[2];

txBuf[0] = (lmx_frame >> 8) & 0xFFFF;
txBuf[1] = (lmx_frame & 0xFF) << 8;

How can I avoid redefine the txBuf?

Best regards,

Lin

Hi Ming,

BTW, if I hard code the txBuf as below

uint16_t txBuf[2] = {0x1AAA, 0x5500};

there will be no error. However, it's not flexible.

Do need your help to fix those errors.

Best regards,

Lin

Hi Ming,

FYI, once I put those parts of code into the void mibspi_loopback_main(void *args) () function, the errors and warning are gone. Now it passes the project build. I will focus on the debugging and testing.

Best regards,

Lin

Thanks Ming,

I get same error messages, if I put the part of code outside of the function. However, As I said in previous message, if I move those parts of code into the function, it works well. Now my code is as below FYI.

#include <kernel/dpl/DebugP.h>
#include <kernel/dpl/SemaphoreP.h>
#include <kernel/dpl/HwiP.h>
#include <kernel/dpl/ClockP.h>
#include <drivers/mibspi.h>
#include "ti_drivers_config.h"
#include "ti_drivers_open_close.h"
#include "ti_board_open_close.h"
/*
uint32_t lmx_frame = 0x1AAA55;
uint16_t txBuf[2] = {0x1AAA, 0x5500};
uint16_t rxBuf[2] = { 0 };
*/
/*
uint8_t const reg_addr = 0x1A; /// uint8_t const, no need
uint16_t const reg_data = 0xAA55; /// uint16_t const, no need

uint32_t lmx_frame = (0U << 23) | (reg_addr << 16) | reg_data; // 24-bit frame from LMX2595

uint16_t txBuf[2] = {0};
uint16_t rxBuf[2] = {0};

txBuf[0] = (uint16_t)(lmx_frame >> 8) & 0xFFFF; // Upper 16 bits
txBuf[1] = (uint16_t)(lmx_frame & 0xFF) << 8; // Lower 8 bits aligned to MSB
*/

void mibspi_loopback_main(void *args)
{
int32_t transferOK;
MIBSPI_Transaction spiTransaction;

uint8_t reg_addr = 0x1A; /// uint8_t const, no need
uint16_t reg_data = 0xAA55; /// uint16_t const, no need

uint32_t lmx_frame = (0U << 23) | (reg_addr << 16) | reg_data; // 24-bit frame from LMX2595

uint16_t txBuf[2] = {0};
uint16_t rxBuf[2] = {0};

txBuf[0] = (lmx_frame >> 8) & 0xFFFF; // Upper 16 bits
txBuf[1] = (lmx_frame & 0xFF) << 8; // Lower 8 bits aligned to MSB

Drivers_open();
Board_driversOpen();

DebugP_log("[MIBSPI] MSS_SPIB_J16 started ...\r\n");

/* Initiate transfer */
spiTransaction.count = 2; /// 2 16-bit data for 24-bit frame
spiTransaction.txBuf = (void *)txBuf;
spiTransaction.rxBuf = (void *)rxBuf;
spiTransaction.peripheralIndex = 0U;
spiTransaction.arg = NULL;

/// check the handle is created well
DebugP_log("SPIB Handle Address: 0x%x\r\n", gMibspiHandle[MSS_SPIB_J16]);

/// start SPI transfer
transferOK = MIBSPI_transfer(gMibspiHandle[MSS_SPIB_J16], &spiTransaction);

/// check the transfer results
DebugP_log("transferOK = %d, spiTransaction.status = %d\r\n", transferOK, spiTransaction.status);

if((SystemP_SUCCESS != transferOK) ||
(MIBSPI_TRANSFER_COMPLETED != spiTransaction.status))
{
DebugP_log("SPI transfer failed!\r\n");
DebugP_assert(FALSE); /* MIBSPI transfer failed!! */
}
else
{
DebugP_log("SPI transfer succeeded!\r\n");
}

Board_driversClose();
Drivers_close();

return;
}

Before checking and verifying SPI signals on J16 header, I have some questions.

My MIBSPI settings in exampl.syscfg file are as below:

example.syscfg / TI DRIVERS (20) / MIBSPI 2/4

Name MSS_SPIB_J16
Mode of Operation Controller
Clock Frequency (Hz) 5000000
Transmit End Delay 0x0
Chip Select Active Delay 0x0
Delay Between Transmissions 0x0
Data Size 16
Frame Format Mode 0 (POL0 PHA0)
Transfer Mode Blocking
Enable Multi ICount Support unchecked
Transfer Timeout 0xFFFFFFFF
Pin Mode 4 Pin Mode with CS
Shift Format MSB shift out first
Enable DMA unchecked
Number of Transfer Groups 1
Show Advanced Config unchecked
XBar Instance MSS_MIBSPIB
SPI Instance MSS_MIBSPIB
Signals Pins Up/Down
MIBSPI CLK Pin(MSS_MIBSPIB_CLK) PAD_CV/V19 Pull Up
MIBSPI MISO Pin(MSS_MIBSPIB_MISO) PAD_CU/V18 Pull Up
MIBSPI MOSI Pin(MSS_MIBSPIB_MOSI) PAD_CT/U19 Pull Up
MIBSPI Channel Configuration
MIBSPI Channel Configuration 0
Peripheral Chip-select 0
DMA Request Line 0
Signals Pins
CS Pin PAD_CX/W18 No Pull

For the 4 SPI signals, there are some other PAD choices available. Which one will be the correct one for connecting to J16 header pin? Or any of them are correct?

For my above settings and code, how can I verify the SPI signals on J16 of EVM?

Detailed instructions are appreciated.

Best regards,

Lin

Hi Ming,

One more question. Which pin or TP can I use as a ground when I measure J16 pin signals with scope?

Thanks,

Lin

Thanks Ming, Got it.

Could you verify my 4 pin's PAD choices?

Best regards,

Lin

Hi Ming,

FYI, I have done the testing SPI signals on J16 of EVM. 

Only one set of pad mapping is working as below:

MIBSPI CLK Pin(MSS_MIBSPIB_CLK) PAD_AJ/D18
MIBSPI MISO Pin(MSS_MIBSPIB_MISO) PAD_AI/C19
MIBSPI MOSI Pin(MSS_MIBSPIB_MOSI) PAD_AH/C18
CS Pin PAD_AA/E18

CS Signal on the R5 pin of J16 is very, not a clean lower level square signal. Only can capture one group of signal and MOSI data only match with upper 16-bit data. Can't display the lower 16-bit data on the scope.

Do you have any comments or explanation on the above results?

Best regards,

Lin

Hi Ming,

Thank you very much for your information.

Yes, by try errors I find D19 is good choice for CS0. However, is there a better way to find it such as by reading and tracing on schematics or the other design documents? Or how did you know D19, F2 and U17 are good ones?

I will pay attention to the signal levels.

Best regards,

Lin

Hi Ming,

So Far the MSS_SPIB 4 pin mode is working well and I have verified by checking the signal with scope. Thank you very much for your help and support.

Now I want to focus on MSS_SPIB 3 pin mode + GPIO pins as CS function.

Could you give more detailed instruction on one example pin as: DBG_SPI_CS0 (MSS_SPIB_CS0 -> MSS_MIBSPIB_CS0 -> D19 mode 0 -> MSS_GPIO_4, according to Table 5-1 in AM273x datasheet).? When I check datasheet Table 5-1, I am still not confident what I should do.

Appreciate your help and time.

Best regards,

Lin

Hi Ming,

Thank you for your detailed instruction and explanation. I will try to set it and test it. I will update you my status.

Best regards,

Lin

Hi Ming,

Here is my latest status.

I made following modifications:
1) .syscfg
A) Pin Mode 3 Pin Mode
B) unchecked CS Hold Enable under Advanced Config
C) unchecked Show Advanced Config
D) add GPIO setting
Name GPIO_LMX_CS
PIN Direction Output
Trigger Type None
Trigger Level Low
Open Drain Disable
XBar Instance MSS_GPIO
GPIO Peripheral MSS_GPIO0
Signals Pins Pull Up/Down
GPIO Pin(MSS_GPIO4) PAD_AK/D19 No Pull
2) mibspi_loopback.c
A) #include <drivers/gpio.h>
B) uint32_t gpioBaseAddr, pinNum;
C) /* Get address after translation translate */
gpioBaseAddr = (uint32_t) AddrTranslateP_getLocalAddr(GPIO_LMX_CS_BASE_ADDR);
pinNum = GPIO_LMX_CS_PIN;
GPIO_setDirMode(gpioBaseAddr, pinNum, GPIO_LMX_CS_DIR);
D) GPIO_pinWriteLow(gpioBaseAddr, pinNum); // Assert CS (Active Low)
transferOK = MIBSPI_transfer(gMibspiHandle[MSS_SPIB_J16], &spiTransaction);
GPIO_pinWriteHigh(gpioBaseAddr, pinNum); // Deassert CS

After build and run my latest code, I can get SPI CLK and SPI MOSI signals from the pins of J16 on the EVM, but I can NOT get the GPIO CS signal from the pin 7 of J7 on the EVM. However, I CAN get the GPIO CS signal on the CS0 pin of the J16.

The S2 was set to PMIC_SPI position as before, not changed.

If I change S2 to DBG_SPI position, no CLK and MOSI on J16, and still NO GPIO CS signal on the pin 7 of J7.

Are all my above results correct? Did I miss anything to get the GPIO CS signal from the pin7 of J7?

Could you help me to check it? Or could you share your correct setting?

Best regards,

Lin

Hi Ming,

S2 to PMIC_SPI, the results are reasonable. However, when S2 to DBG_SPI, I checked pin7 of J7 very carefully, it has no 3.3V signal toggle. GPIO part of code is same not change. Could you or any other member verify it on your side?

Best regards,

Lin

Hi Ming,

Thank you so much for you sharing the results with me. Although I can't get the same results as yours on my EVM, I will assume that it working for me.

When we design our prototype we will pay attention to that.

Two more questions for you before we close this case. Where are you physically located? Is it possible for you to provide in person support either you come to our office in Huntington Beach, CA US or I can go to your office with my boards?

Best regards,

Lin

Hi Lin,

Are you using the ZX100-QTH030-ST Samtec Breakout Adapter on J7 to get the pin7 and Saleae Logic Pro to capture the signals?

Have you connected the pin8 of J7 for GND?

Best regards,

Ming

Hi Ming, 

Thank you very much for your follow up questions. 

I have ordered the  ZX100-QTH030-ST Samtec Breakout Adapter for my test, it will arrive my office next Monday. I just asked our technician to solder a test wire from pin 7 of the J7. And I used RIGOL MSO5104 scope to capture the signal not Saleae Logic Pro.

No, I still use pin 29 and 26 of J24 as GND not pin8 of J7. Do I have to use the pin 8 as GND to capture the signal on pin 7 of J7?

Best regards,

Lin