uPP Channel A (TX) to B (RX)

Vijay Varma

In our design we are using AM1810BZWTA3 processor.Currently we are testing uPP in 8 bit with loopback mode Channel A to B & Channel B to A.

1/ Channel A to B:

Upp Register Configurations :

a/ uPP_UPCTL Register Value---->0x00000007 (A is Tx and B is Rx)

b/ uPP_UPICR Register Value---->0x00180020 (Signals are enabling related to A(Tx) and B(Rx))

c/ uPP_UPTCR Register Value---->0x00030303 (Transmit threshold and Read threshold for DMA Channel Q and I are set to 256 bytes)

d/ Digital Loop Back A to B is Enabled uPP_UPDLB = 0x00001000

Dma Related Configuration :

Channel-Q is Receive

Channel-I is Transmit

Line_Count = 1;

Byte_Count = 4096;

Line_Offset_Count = 0;

When we run the Upp with the above Configuration settings in Arm1810, In Inturrept routine continiously Underrun or Overflow Inturrept related to Channel-I are getting, But data corruption is not happening(Data size is 4k(4096)).

The following output as shown below:

TxBuff b b b

RxBuff

bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb

Underrun or Overflow Inturrept Occured for Channel- I

TxBuff c c c

RxBuff

cccccccccccccccccccccccccccccccc

Underrun or Overflow Inturrept Occured for Channel -I

2/ Channel B to A:

The same configuration parameters used & working fine.

Kindly let us known your feedback/ suggestions for Channel A to B issue for Underrun or Overflow Inturrept Occuring.

over 11 years ago

0 Biser Gatchev-XID over 11 years ago

TI__Guru**** 393215 points

Moving this to the proper forum.

0 Pubesh over 11 years ago

TI__Mastermind 20790 points

Vijay Varma,

Please check the below configurations for UPP

UPCTL.value=0;
UPCTL.bits.IWB = 1; //16 bit interface
UPCTL.bits.DPWB = 2; //10 bit data

UPCTL.bits.DPFA = 0;
UPCTL.bits.DPWA = 2;
UPCTL.bits.IWA = 1;

UPCTL.bits.CHN = 1; //dual channel mode
UPCTL.bits.MODE = 2; //0 all recv, 1 all xmit, 2 a recv b xmit, 3 a xmit b recv
//Channel A ADC, Channel B DAC

UPICR.value=0;

UPIVR.value=0;
UPIVR.bits.VALB = 0x1000;
UPIVR.bits.VALA = 0x0000;

UPTCR.value=0; //all values 0 for 64byte DMA bursts read / write
UPDLB.value=1; //loopback
UPIES.value=0; //dont enable any interrupts
UPPCR.value = 0;
UPPCR.bits.EN = 1; //enable uPP
UPPCR.bits.RTEMU = 1; //allow emulator use
UPPCR.bits.SOFT = 1; //allow emulation

If interrupt enabled, Watch for interrupt events. Reprogram the DMA as necessary (checking that the PEND bit in the uPP DMA channel status register (UPxS2) is 0).

System Priority:
When the uPP operates in parallel with EDMA, assigning higher priority to the uPP may help the uPP avoid underflow or overflow conditions.

You can find the reference code for uPP in a digital loopback mode at the wiki article,
http://processors.wiki.ti.com/index.php/Using_the_uPP_EVM_example_applications_from_the_BIOS_PSP

0 Vijay Varma over 11 years ago in reply to Pubesh

Intellectual 260 points

Pubesh,

We have tried with above suggested configurations,but data corruption is happening.

We tried with 16 bit configuration A to B Upp Loop Back Mode, with below configurations issues are observed.

TX-->Channel-A and RX--->Channel-B (A-to-B)
Upp Configurations and settings
Clk-75Mhz
uPP_UPCTL----->0x02020007
uPP_UPICR----->0x00180020
uPP_UPIVR----->0x0000FFFF
uPP_UPTCR----->0x00030303
uPP_UPDLB----->0x00001000

-----------Dma Related Configurations-----
Every Packet size is 4k (unsigned short 4096 size)
allocation of memory kmalloc(MAX_SIZE, GFP_DMA).
and mapping the memory using dma_map_single API
Line_count = 1
Dma Transaction Size is = (4096) bytes
Line_offset = 0
-------------------------------------------
Observed issue :
At the receiving end always 12 to 15 bits are corruption is happening out of (0 t0 15 bits)

0 Pubesh over 11 years ago in reply to Vijay Varma

TI__Mastermind 20790 points

Vijay Varma,

Take this as a reference code for UPP, and modify or configure the UPP to according your target / device.

5224.ARM EVM UPP Test.zip

0 mrudula chougule over 11 years ago in reply to Pubesh

Prodigy 160 points

Hi All,

I am working on the SBC8018 board for upp driver. I am able to build and install the upp driver code given on the below link,

I am trying to run loop back using linux upp driver code.

I have allocated statically tx/rx buffer. While reading rx buffer I am always getting value as 0.

Could you please let me know, is static buffer allocation affect this DMA operation.

Here is my upp configuration,

UPPID = 44231100
UPPCR =       8a
UPDLB =     1000
RSVD0 =        0
UPCTL =        7
UPICR =        0
UPIVR =        0
UPTCR =        0
UPISR =     1010
UPIER =        0
UPIES =        0
UPIEC =        0
UPEOI =        0
            =        0
        =        0
      =        0
UPID0 = c6df0068
UPID1 =    10040
UPID2 =        0
        =        0
UPIS0 = c6df0068
UPIS1 =    20000
UPIS2 =       80
      =        0

UPQD0 = c6df2210

UPQD1 =    10040
UPQD2 =        0
        =        0
UPQS0 = c6df2210
UPQS1 =    20000
UPQS2 =       80
   =        0
With this configuration I am always getting rx buffer value as zero.

Please let me know any modification do I need to make on kernel side to make it work.

Thanks

Mrudula

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uPP Channel A (TX) to B (RX)