OMAP L138 I2C1 interface doesn't work

Hi Roland,

Are you saying the same code works when you drop a C6748 SOM, but not when you drop in a OMAPL138 part? If that's the case, I would first check on logicPD website to make sure the SOM and baseboard are compatible. You also need to make sure you OMAPL138 SOM is not damaged. =)

regards,

Paul

Hi Paul,

that's true, C6748 SOM works, OMAPL138 does not (with identical code). Following your recommendation I came to these results:

• I couldn't find any indication regarding incompatibility of SOM and baseboard. Furthermore, baseboard and SOM cam with the same ZOOM EVM, so they should be compatible, right?
• I also dropped another OMAP L138 SOM, which did not work as well (so OMAP seems not to be damaged).

After all, to me it seems that OMAP I2C is not working. When I attach a logic analyzer to the SDA and SCKL wires, I can see bus activity (start bit) but it stops before slave address appears. On the baseboard the were a RS232 transceiver attached to the I2C1 pin, but I removed it prior to my checks. SOM has no I2C slaves on I2C1, so my 2 external I2C devices are the onlöy slaves that are attached to I2C1.

Any other ideas?

Regards,

Roland

Roland,

This is really weird. Is there a simple testcase that you can send it to me to quick test it out locally? Preferablly with a failure/pass checking mechanism.

regards,

Paul

Paul,

sorry I'm not allowed to post an example. If you send me your email address to my registered email address, I'll send you a reduced and modified code that shows the effect.

Regards,

Roland

What's the ARM core doing while you're running this code on the DSP?  Are you sure it's not running Linux and perhaps getting in the way?

What's the SCL frequency for the little bit of activity that you're seeing?  Please dump the I2C registers just before you kick off the transaction and just after it fails.

Hi Brad,

• ARM core does nothing, it's just turned on. I don't run Linux on it.
• SCL frequency of the single clock signal is 400 kHz as expected.
• I2C registers have correct content (driver works on single core C6748 and register content is identical to OMAP).

Regards,

Roland

I assume this issue is still unresolved?  After you've unsuccessfully attempted to run your code, can you load this gel file and do the "Run All" script:

http://processors.wiki.ti.com/index.php/OMAP-L1x_Debug_Gel_Files

Please paste the results into a txt file and attach to a reply.

Thanks,
Brad

Hi Brad,

here is the output:

C674X_0: GEL Output: ---------------------------------------------
C674X_0: GEL Output: |             Device Information            |
C674X_0: GEL Output: ---------------------------------------------
C674X_0: GEL Output: DEV_INFO_00 = 0x1B7D102F
C674X_0: GEL Output: DEV_INFO_01 = 0x00000000
C674X_0: GEL Output: DEV_INFO_02 = 0x0000000C
C674X_0: GEL Output: DEV_INFO_03 = 0x00000032
C674X_0: GEL Output: DEV_INFO_04 = 0x00000000
C674X_0: GEL Output: DEV_INFO_05 = 0x000003E0
C674X_0: GEL Output: DEV_INFO_06 = 0x08000200
C674X_0: GEL Output: DEV_INFO_07-DEV_INFO_08-DEV_INFO_09-DEV_INFO_10-DEV_INFO_11-DEV_INFO_12 = 0-0-5929125-14-48-26
C674X_0: GEL Output: DEV_INFO_13,DEV_INFO_14,DEV_INFO_15,DEV_INFO_16 = 2,0,0,10514
C674X_0: GEL Output: -----
C674X_0: GEL Output: DEV_INFO_17 = 0x00030003
C674X_0: GEL Output: DEV_INFO_18 = 0x00000000
C674X_0: GEL Output: DEV_INFO_19 =C674X_0: GEL Output: 0C674X_0: GEL Output: 0C674X_0: GEL Output: 0C674X_0: GEL Output: 0C674X_0: GEL Output: 0C674X_0: GEL Output:
C674X_0: GEL Output: -----
C674X_0: GEL Output: DEV_INFO_20 = 0x30303864
C674X_0: GEL Output: DEV_INFO_21 = 0x3630306B
C674X_0: GEL Output: DEV_INFO_22 = 0x00000000
C674X_0: GEL Output: DEV_INFO_23 = 0x00000000
C674X_0: GEL Output: -----
C674X_0: GEL Output: DEV_INFO_24 = 0x0E01A030
C674X_0: GEL Output: DEV_INFO_25 = 0x005A78A5
C674X_0: GEL Output: DEV_INFO_06 = 0x08000200
C674X_0: GEL Output: DEV_INFO_26 = 0x52240002
C674X_0: GEL Output:

C674X_0: GEL Output: ---------------------------------------------
C674X_0: GEL Output: |               BOOTROM Info                |
C674X_0: GEL Output: ---------------------------------------------
C674X_0: GEL Output: ROM ID: d800k006
C674X_0: GEL Output: Silicon Revision 2.0
C674X_0: GEL Output: Boot pins: 12
C674X_0: GEL Output: Boot Mode: SPI1 Flash
C674X_0: GEL Output:
ROM Status Code: 0x00000000
Description:C674X_0: GEL Output: No error
C674X_0: GEL Output:
Program Counter (PC) = 0xC316194C
C674X_0: GEL Output:
C674X_0: GEL Output: ---------------------------------------------
C674X_0: GEL Output: |              Clock Information             |
C674X_0: GEL Output: ---------------------------------------------
C674X_0: GEL Output:
C674X_0: GEL Output: PLLs configured to utilize crystal.
C674X_0: GEL Output: ASYNC3 = PLL0_SYSCLK2
C674X_0: GEL Output:
C674X_0: GEL Output: NOTE:  All clock frequencies in following PLL sections are based
C674X_0: GEL Output: off OSCIN = 24 MHz.  If that value does not match your hardware
C674X_0: GEL Output: you should change the #define in the top of the gel file, save it,
C674X_0: GEL Output: and then reload.
C674X_0: GEL Output:
C674X_0: GEL Output: ---------------------------------------------
C674X_0: GEL Output: |              PLL0 Information             |
C674X_0: GEL Output: ---------------------------------------------
C674X_0: GEL Output:
C674X_0: GEL Output: PLL0_SYSCLK1 = 300 MHz
C674X_0: GEL Output: PLL0_SYSCLK2 = 150 MHz
C674X_0: GEL Output: PLL0_SYSCLK3 = 25 MHz
C674X_0: GEL Output: PLL0_SYSCLK4 = 75 MHz
C674X_0: GEL Output: PLL0_SYSCLK5 = 100 MHz
C674X_0: GEL Output: PLL0_SYSCLK6 = 300 MHz
C674X_0: GEL Output: PLL0_SYSCLK7 = 50 MHz
C674X_0: GEL Output:
C674X_0: GEL Output: ---------------------------------------------
C674X_0: GEL Output: |              PLL1 Information             |
C674X_0: GEL Output: ---------------------------------------------
C674X_0: GEL Output:
C674X_0: GEL Output: PLL1_SYSCLK1 = 300 MHz
C674X_0: GEL Output: PLL1_SYSCLK2 = 150 MHz
C674X_0: GEL Output: PLL1_SYSCLK3 = 100 MHz
C674X_0: GEL Output:
C674X_0: GEL Output: ---------------------------------------------
C674X_0: GEL Output: |              PSC0 Information             |
C674X_0: GEL Output: ---------------------------------------------
C674X_0: GEL Output:
C674X_0: GEL Output: State Decoder:
C674X_0: GEL Output:  0 = SwRstDisable (reset asserted, clock off)
C674X_0: GEL Output:  1 = SyncReset (reset assered, clock on)
C674X_0: GEL Output:  2 = Disable (reset de-asserted, clock off)
C674X_0: GEL Output:  3 = Enable (reset de-asserted, clock on)
C674X_0: GEL Output: >3 = Transition in progress
C674X_0: GEL Output:
C674X_0: GEL Output: Module 0:    EDMA3CC (0)        STATE = 3
C674X_0: GEL Output: Module 1:    EDMA3 TC0          STATE = 3
C674X_0: GEL Output: Module 2:    EDMA3 TC1          STATE = 3
C674X_0: GEL Output: Module 3:    EMIFA (BR7)        STATE = 3
C674X_0: GEL Output: Module 4:    SPI 0              STATE = 3
C674X_0: GEL Output: Module 5:    MMC/SD 0           STATE = 3
C674X_0: GEL Output: Module 6:    AINTC              STATE = 3
C674X_0: GEL Output: Module 7:    ARM RAM/ROM        STATE = 3
C674X_0: GEL Output: Module 9:    UART 0             STATE = 3
C674X_0: GEL Output: Module 10:    SCR 0 (BR0/1/2/8)  STATE = 3
C674X_0: GEL Output: Module 11:    SCR 1 (BR4)        STATE = 3
C674X_0: GEL Output: Module 12:    SCR 2 (BR3/5/6)    STATE = 3
C674X_0: GEL Output: Module 13:    PRUSS              STATE = 0
C674X_0: GEL Output: Module 14:    ARM                STATE = 3
C674X_0: GEL Output: Module 15:    DSP                STATE = 3
C674X_0: GEL Output:
C674X_0: GEL Output: ---------------------------------------------
C674X_0: GEL Output: |              PSC1 Information             |
C674X_0: GEL Output: ---------------------------------------------
C674X_0: GEL Output:
C674X_0: GEL Output: State Decoder:
C674X_0: GEL Output:  0 = SwRstDisable (reset asserted, clock off)
C674X_0: GEL Output:  1 = SyncReset (reset assered, clock on)
C674X_0: GEL Output:  2 = Disable (reset de-asserted, clock off)
C674X_0: GEL Output:  3 = Enable (reset de-asserted, clock on)
C674X_0: GEL Output: >3 = Transition in progress
C674X_0: GEL Output:
C674X_0: GEL Output: Module 0:    EDMA3CC (1)        STATE = 3
C674X_0: GEL Output: Module 1:    USB0 (2.0)         STATE = 3
C674X_0: GEL Output: Module 2:    USB1 (1.1)         STATE = 3
C674X_0: GEL Output: Module 3:    GPIO               STATE = 3
C674X_0: GEL Output: Module 4:    UHPI               STATE = 3
C674X_0: GEL Output: Module 5:    EMAC               STATE = 3
C674X_0: GEL Output: Module 6:    DDR2 and SCR F3    STATE = 3
C674X_0: GEL Output: Module 7:    MCASP0 + FIFO      STATE = 3
C674X_0: GEL Output: Module 8:    SATA               STATE = 3
C674X_0: GEL Output: Module 9:    VPIF               STATE = 3
C674X_0: GEL Output: Module 10:    SPI 1              STATE = 3
C674X_0: GEL Output: Module 11:    I2C 1              STATE = 3
C674X_0: GEL Output: Module 12:    UART 1             STATE = 3
C674X_0: GEL Output: Module 13:    UART 2             STATE = 3
C674X_0: GEL Output: Module 14:    MCBSP0 + FIFO      STATE = 3
C674X_0: GEL Output: Module 15:    MCBSP1 + FIFO      STATE = 3
C674X_0: GEL Output: Module 16:    LCDC               STATE = 3
C674X_0: GEL Output: Module 17:    eHRPWM (all)       STATE = 3
C674X_0: GEL Output: Module 18:    MMC/SD 1           STATE = 3
C674X_0: GEL Output: Module 19:    UPP                STATE = 3
C674X_0: GEL Output: Module 20:    eCAP (all)         STATE = 3
C674X_0: GEL Output: Module 21:    EDMA3 TC2          STATE = 3
C674X_0: GEL Output: Module 24:    SCR-F0 Br-F0       STATE = 3
C674X_0: GEL Output: Module 25:    SCR-F1 Br-F1       STATE = 3
C674X_0: GEL Output: Module 26:    SCR-F2 Br-F2       STATE = 3
C674X_0: GEL Output: Module 27:    SCR-F6 Br-F3       STATE = 3
C674X_0: GEL Output: Module 28:    SCR-F7 Br-F4       STATE = 3
C674X_0: GEL Output: Module 29:    SCR-F8 Br-F5       STATE = 3
C674X_0: GEL Output: Module 30:    Br-F7 (DDR Contr)  STATE = 3
C674X_0: GEL Output: Module 31:    L3 RAM, SCR-F4, Br-F6 STATE = 3

Regards,

Roland

Looks normal...

Can you dump your I2C registers before and after the transaction?

Hi Roland,

Thank you for reporting back this info to the forum.  It's very strange indeed.  A colleague suggested that perhaps the behavior is related to the Suspend Source Register (SUSPSRC).  You can find that register documented in Section 11.5.11 of the TRM.

Best regards,
Brad

Has this problem get be solved? 

Does the peripheral work?

There are no known issues with respect to I2C1.  I was just looking at the LogicPD EVM schematics and wondering if perhaps there's some kind of board issue related to using I2C1.  There's a lot of pin muxing on those pins, e.g. they also happen to be UART pins.  In fact, I see a TRS3386ECPWR device hooked up to those pins.  In particular that device has a /PWRDOWN pin on it which would disable the outputs.  Have you tried changing the population of that pin such that you disable the TRS3386E?  Also, what is the voltage level of whatever you've connected to the I2C bus?  Seems like there could be opportunity for things to get mixed up due to the dual-voltage support on these pins.

Brad,

We are using a customized board. Though the I2C1 pins are multipled with others, it should not be a cause of problem as long as Pinmux registers are set. However one question I have with pinmuxing is:

// pinmux defines.
#define PINMUX_I2C0_REG       (4)
#define PINMUX_I2C0_MASK      (0x0000FF00)
#define PINMUX_I2C0_VAL       (0x00002200)
#define PINMUX_I2C1_REG       (4)
#define PINMUX_I2C1_MASK      (0x00FF0000)
#define PINMUX_I2C1_VAL       (0x00440000)

Though pinmux register for both I2C0 and I2C1 are pinmux 4, the value to set them as I2C pins are different (2 for I2C0 and 4 for I2C1). I had suspected that 4 for I2C1 was a typo both in the TRM and the BSL. However changing it to 2 as I2C0 doesn't solve the problem.

Regarding power group, DVDD3318_A, DVDD3318_B and DVDD3318_C all use the same 1.8V voltage and have been merged as one single group.

On the logic PD EVM does the I2C1 really work? Could someone run a test and measure the pins to make sure it is really error-free?

There should be no issue on I2C1 from a device perspective.

Can you also check if you are adjusting the I2C1 module clock as documented here

http://processors.wiki.ti.com/index.php/StarterWare_01.10.01.01_User_Guide#I2C

if this fixes your issue, this might be something that we need to highlight in the System user guide in the device clocking chapter.

Regards

Mukul