problem using LINRX as GIO on TMS570LS1224

Miguel Amezcua Peregrina

Other Parts Discussed in Thread: HALCOGEN

hi everyone!!

I have been strugling with the LINRX pin of the MCU... Im using that pin for the pin direction of a driver for motor control. Th LINTX works without problem, but for some reason, the RX is not leveling up...

Here is the LIN configuration I used.

I even tried to change the value here, it did, but I cannot drive it to low...

I even checked the memory registers

and here is the lin.c file (justthe registers part)

as you can see, the PIO0 is configured as non functional, so I can use the pins as GIO, the PIO3 has the output values on low (I change them), the direction for both pins (Rx and TX) are output and the open drain is disable and the pull up resistance is selected but (I dont finish to understand the memory broser to be honest) it seem that the code and the memory browser dont match...

I appreciate the help

thanks!!

over 8 years ago

0 Anthony F. Seely over 8 years ago

TI__Guru 68920 points

What happens if you write a value of 0x04 to 'LIN1_Dclr' in the memory browser.

That should drive the pin low based on what i see. At very minimum, the DOUT register should go LOW.

[EDIT: assuming you are using a LaunchPad...

please also check that this pin is not connected directly to the XDS110 as it might be driven by the emulator.]

0 Miguel Amezcua Peregrina over 8 years ago in reply to Anthony F. Seely

Genius 4015 points

ammm I havent checked that... but the 0x04 corresponds to the TX pin no??

The board is one that I designed and for what I saw on the datasheet, the LIN module is completely separated from the JTAG pins...

So what you say is thet I clear the pin value using the register? and how could I set the value again??

What I dont get is why the TX pin works perfectly but not the RX, when both work the same way when they are set to work as GIO...

0 Anthony F. Seely over 8 years ago in reply to Miguel Amezcua Peregrina

TI__Guru 68920 points

yes you're right, so same question but use 0x2...

0 Miguel Amezcua Peregrina over 8 years ago in reply to Anthony F. Seely

Genius 4015 points

mmm nothing... I dont know what happened now that even the TX pin is not changing... and for some extrange reason they are on high leven when I configure them as 0...

0 Miguel Amezcua Peregrina over 8 years ago in reply to Miguel Amezcua Peregrina

Genius 4015 points

I had the sci library and init. not the lin.
I already change that but nothing changed.... I already tried to even put the 0x02 instead of 1 and nothing...

update:

when the time goes, the pin TX does change and the register too:

but even when there is a line for doing the same for the RX pin... is not working...

**Update:

I think it could be a problem with the generated codes from Halcogen on the RX functionality or something... because I can start the pin RX in 1 (congifuring it from the lin.c) but not turning it to low. The same problem...

0 Miguel Amezcua Peregrina over 8 years ago in reply to Anthony F. Seely

Genius 4015 points

I tried commenting the line that sets the register to try avoid the overwrite but nothing...

0 Anthony F. Seely over 8 years ago in reply to Miguel Amezcua Peregrina

TI__Guru 68920 points

Miguel,

Did you ever check your board to make sure that no other chip is driving the LINRX pin?

If you are using a launchpad then you would be driven by the XDS110 on this pin.

0 Miguel Amezcua Peregrina over 8 years ago in reply to Anthony F. Seely

Genius 4015 points

I did... I even have the schquematic here with me and the only place where it appears is on the drivers section... (I cant upload the full schematic) but its nos being used by any other module. Why on the Launchapd is being used by the XDS110??

look:

0 Anthony F. Seely over 8 years ago in reply to Miguel Amezcua Peregrina

TI__Guru 68920 points

Ok then if it's custom hardware that's fine.

Ont he launchpad it's driven by the XDS110 because the XDS110 has a USB - Serial port feature, so that you can communicate w. the LIN through a COM port on the host PC.

It doesn't look like there is any conflict though on your hardware based on the schematic.

0 Anthony F. Seely over 8 years ago in reply to Anthony F. Seely

TI__Guru 68920 points

BTW do you actually have an LS1224 soldered to the board, or is it a different part #?

There is an LS1227 that sometimes is recommended as a replacement for the 1224 and while it is a superset theoritically it has slightly different pinout because of FlexRay.

0 Miguel Amezcua Peregrina over 8 years ago in reply to Anthony F. Seely

Genius 4015 points

Its a LS1224. I accidentaly ordered the LS1227 but then I saw the FlexRay and those were dead pins for me so I re-order and got the LS1224

0 Anthony F. Seely over 8 years ago in reply to Miguel Amezcua Peregrina

TI__Guru 68920 points

So please paste the entire range 0xFFF7E43C - 0xFFF7E45C just so we can see all the GIO port registers.

0 Miguel Amezcua Peregrina over 8 years ago in reply to Anthony F. Seely

Genius 4015 points

Here it is

0 Anthony F. Seely over 8 years ago in reply to Miguel Amezcua Peregrina

TI__Guru 68920 points

Super.
Ok that screeenshot looks fine.

Now please write 0x06 to Lin1_DSET and then show me what the result is.

I want to see that Dout goes to 0x06, then I want to see what happens on DIn.

0 Miguel Amezcua Peregrina over 8 years ago in reply to Anthony F. Seely

Genius 4015 points

It changed (and the pin) but it doesnt goes down when the code orders that...

0 Miguel Amezcua Peregrina over 8 years ago in reply to Anthony F. Seely

Genius 4015 points

and now I cant drive the pin to low hahaha I wrote 0x00 tu turnboth pins to low and nothing... only the TX changed

0 Anthony F. Seely over 8 years ago in reply to Miguel Amezcua Peregrina

TI__Guru 68920 points

So you've got a software problem then.

0 Miguel Amezcua Peregrina over 8 years ago in reply to Anthony F. Seely

Genius 4015 points

yep... but I have no idea of whats going on... because I generated the codes with Halcogen and I already checked them and everything looks fine...

0 Anthony F. Seely over 8 years ago in reply to Miguel Amezcua Peregrina

TI__Guru 68920 points

Check this:

1) step through the register writes in assembly. You will get to an assembly statement like
STR R0, [R12] or something.
Look at what is in those registers - you want to see the correct adress in one register and correct data
in the other.

2) make sure the instruction is STR. If it is STRB or STRH then you need to really double check the register address for the ENDIAN of the CPU which is BIG ENDIAN if the device is LS1224. If it's a 32-bit write (STR) the endian becomes a non-issue...

3) check the MPU settings to make sure you've allowed the CPU to access these registers
and check the CPU mode to see if it's user or privileged (like System) when that code is executing.

0 Miguel Amezcua Peregrina over 8 years ago in reply to Anthony F. Seely

Genius 4015 points

mmmm but I dont understand why I can change the TX pin without problem but no the RX pin..

here is the image of the dissasembly

0 Anthony F. Seely over 8 years ago in reply to Miguel Amezcua Peregrina

TI__Guru 68920 points

So that disassembly image shows the etpwSetCmpB function doesn't it? Or am I missing something.

Anyway you need to be at the STR instruction and then we can look at the registers in question.

So say it is the strb r12,[r2] we'd also want to not only see the disassmbly but the contents of R12 and R2 right before the strb was executed (PC pointer (blue arrow) should be ON the STRB instruction; in your example it's on the LDRH instruction which is too early; but it's also I think on the wrong line of C code..)

0 Miguel Amezcua Peregrina over 8 years ago in reply to Anthony F. Seely

Genius 4015 points

ammmm no. That image shows everthing from the pwm and below. And Im not too familiar with CCS and I dont know how to open those contents... or where to look for them...
I dont finish to understand the
"So say it is the strb r12,[r2] we'd also want to not only see the disassmbly but the contents of R12 and R2 right before the strb was executed (PC pointer (blue arrow) should be ON the STRB instruction; in your example it's on the LDRH instruction which is too early; but it's also I think on the wrong line of C code..)"

but amm the pointer is under the TX pin and above th RX which, if Im not wrong, is under the etpwmCmpB

0 Miguel Amezcua Peregrina over 8 years ago in reply to Anthony F. Seely

Genius 4015 points

look. I saw this and looks weird... why is there the etpwm function and then the port->DSET and then the second etpwm function but not the port->DSET that corresponds to the RX pin??

what could cause this??

I attarch too the project. (Inside the folder "pwm_todos" is the halcogen proyect and the generated codes. 2352.Codigo_Mano_22_agos_2016.rar

0 Anthony F. Seely over 8 years ago in reply to Miguel Amezcua Peregrina

TI__Guru 68920 points

Good question.

At the same time see below:

See how I put the Green Arrows showing you which lines CCS thinks you are on (in C Source, and corresponding assembly).

Step 1: Please step until you get the Green Bar on the left to highlight line 93 instead of line 92

Step 2: Please then assembly step (Green Step Button, not Yellow) until you reach a STR rx, [ry] type instruction ?

Step 3: Can you finally then please show the CPU registers in the display so we can see what the value in rx, ry are?

Step 3 needs to be done while the cursor is on the correct assembly instruction because registers get reused over and over by the CPU so

looking at them early doesn't help.

0 Miguel Amezcua Peregrina over 8 years ago in reply to Anthony F. Seely

Genius 4015 points

6786.prueba 1.mp4

here is what happened

0 Anthony F. Seely over 8 years ago in reply to Miguel Amezcua Peregrina

TI__Guru 68920 points

Did you compile with heavy optimization turned on? That makes it difficult to step through.

look at the 13 second mark in the video. It appears to be writing a value of 0x10 (r10 contents) to the GIO DSET register. That's not what you want obviously because it's the wrong bit location. Some coding error perhaps in the way that the bit shift is encoded or maybe you're mixing up 0x10 hex with 010b binary?

0 Miguel Amezcua Peregrina over 8 years ago in reply to Anthony F. Seely

Genius 4015 points

I think I did...
and... yes... I think the bit should be on R9 but no... I mean... Im usin 0x2 and 0x4 fr the pin value change...

0 Miguel Amezcua Peregrina over 8 years ago in reply to Anthony F. Seely

Genius 4015 points

what could that be that bit shift? I dont think I mess up that... because im using hex on the code

0 Anthony F. Seely over 8 years ago in reply to Miguel Amezcua Peregrina

TI__Guru 68920 points

Well, look at this:

See (1), this is the instruction that is writing to the DSET register. The address of DSET is in "LR" .. See (3).

But the value written is what is in R10, and that value is 0x10, see (2).

0 Miguel Amezcua Peregrina over 8 years ago in reply to Anthony F. Seely

Genius 4015 points

I change the configuration and put 0 optimization:

0777.capture-2.mp4

0 Anthony F. Seely over 8 years ago in reply to Anthony F. Seely

TI__Guru 68920 points

yeah I think I see it.

you have the meaning of the gioSetBit parameters misunderstood.

The parameters are *port, bit, and value.

Instead of
gioSetBit(linPort, 0x4, 0x4)

do
gioSetBit(linPort, 2, 1)

You want bit 2 set, not bit 4 ! And you want it set to 1 'cause it's a bit and can only take values of 0 or 1...

0 Miguel Amezcua Peregrina over 8 years ago in reply to Anthony F. Seely

Genius 4015 points

why could that be happening??

0 Miguel Amezcua Peregrina over 8 years ago in reply to Anthony F. Seely

Genius 4015 points

ammmm actually... Im using both bits. The 4 (TX) and the 2 (RX). And changing the value to 1, is the same as having the 0x04 or the 0x02... something is hapenning thaat the gioSetBit(linPORT(pinRX),0x2,1/0x02) is not working... but I really have no idea of whats going on...

0 Miguel Amezcua Peregrina over 8 years ago in reply to Anthony F. Seely

Genius 4015 points

look: the minute 2:22 it does change the value on R12 to 2 but then to 4, so the pin doesnt change its value... If Im not wrong, according to the memory browser we checked, the value should be 6, not 4...

1004.capture-3.mp4

0 Anthony F. Seely over 8 years ago in reply to Miguel Amezcua Peregrina

TI__Guru 68920 points

Hi Miguel,

I'm having a hard time following but I think you've shown that you can make the pins go to the state you want by writing the correct value to the pin control register.

So I'd say just try to understand the GIO functions and how the bit shift & encoding works and you'll get through this pretty soon.

0 Miguel Amezcua Peregrina over 8 years ago in reply to Anthony F. Seely

Genius 4015 points

I already tried to write directly into the register and nothing... I mean literally "linREG->PIO3" and didnt work...

0 Miguel Amezcua Peregrina over 8 years ago in reply to Anthony F. Seely

Genius 4015 points

and I repeat myself... the problem is just on that pin. Why is that happening? why is it working on TX pin but not on RX pin?

0 Miguel Amezcua Peregrina over 8 years ago in reply to Anthony F. Seely

Genius 4015 points

I... kinda solve it...
etpwmSetCmpB(etpwmREG1, (etpwmREG1->TBPRD/100)*c);
//gioSetBit(linPORT, 0x02, dir1); //LIN_RX
linREG->PIO3=(uint32)2U; //This value turns on the RX pin

//motor Ring finger
etpwmSetCmpA(etpwmREG1, (etpwmREG1->TBPRD/100)*c);
//gioSetBit(linPORT, 0x04, dir1); //LIN_TX
linREG->PIO3=(uint32)6U; //this value turns on the TX pin when the RX pin is on high too. For only the TX pin, write 4

etpwmSetCmpB(etpwmREG1, (etpwmREG1->TBPRD/100)*c);
//gioSetBit(linPORT, 0x02, dir1); //LIN_RX
linREG->PIO3=(uint32)4U; //this value turns off RX pin and leaves TX pin on high

etpwmSetCmpA(etpwmREG1, (etpwmREG1->TBPRD/100)*c);
//gioSetBit(linPORT, 0x04, dir1); //LIN_TX
linREG->PIO3=(uint32)0U; //this value turns off both pins
__delay_cycles(160000000*3); //delay 3 seconds

by writing directly into the register instead of using the gioSetBit function... I think this is for how the functions of LIN are written. Because the function expects a 2 (for only RX) or a 4 (for only TX) or a 6 (for both) or a 0 (to turn off both)...

Update

I hope this helps others trying to use the LIN pins as GIO. I don't recomend using gioSetBit function because how it works. It changes the value of an specific bit and in this particular case, the register doesn't work with bits. It expects a value of 2, 4 or 6. Your one means 2 or 4 or 6 and your 0 means 0 or a -2 or a -4 or a -6 (depending on the value of the register)

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problem using LINRX as GIO on TMS570LS1224