AM3358: GPMC can not read correct data from FPGA

Shine

Part Number: AM3358

Hello Champs,

Customer connected AM335x GPMC to FPGA, GPMC worked in async mode. GPMC writing operation is correct, but AM335x GPMC could not read correct data from FPGA, it read the next data instead. Below is the timing wave from FPGA.

When GPMC_addr = 0D, the expected data GPMC_data = 0FFF, but the next data 0FDF is read instead.

How to resolve the issue?

Thanks.
Rgds
Shine

over 7 years ago

0 Biser Gatchev-XID over 7 years ago

TI__Guru**** 393215 points

Hi,

What software is this? Which version?

0 sheng liu over 7 years ago in reply to Biser Gatchev-XID

Prodigy 20 points

Hi,

The FPGA is Spartan6 serial and designed by ISE14.7. So the read-back waveform is captured by ISE ChipScope tool.

Best regards,

0 Biser Gatchev-XID over 7 years ago in reply to sheng liu

TI__Guru**** 393215 points

My question was what software/version is running on the AM335x.

0 sheng liu over 7 years ago in reply to Biser Gatchev-XID

Prodigy 20 points

My software enviroment is Linux3.2.0.

0 Shine over 7 years ago in reply to Biser Gatchev-XID

TI__Genius 13655 points

Hi Biser,

Below is the snapshot of customer's GPMC registers configuration.

GPMC_CONFIG1 : 0x00001000
GPMC_CONFIG2 : 0x00111100
GPMC_CONFIG3 : 0x22060614
GPMC_CONFIG4 : 0x10057015
GPMC_CONFIG5 : 0x00101111
GPMC_CONFIG6 : 0x84000000
GPMC_CONFIG7 : 0x00000F42

Thanks.
Rgds
Shine

0 Mark M over 7 years ago in reply to Shine

TI__Mastermind 30170 points

Hi Shine,

Parsing the GPMC registers you provided...

RDACCESSTIME = 16

OEOFFTIME = 16

RDCYCLETIME = 17

Keeping RDACCESSTIME set to 16...

Try to extend OEOFFTIME from 16 to (RDACCESSTIME + 1 ) = 17 or more.

Try to extend RDCYCLETIME from 17 to (OEOFFTIME + 1) = 18 or more.

What are the contents of the GPMC_CONFIG Register?

WAIT0PINPOLARITY selects the polarity of input pin WAIT0

0h (R/W) = WAIT0 active low (low means data invalid)

1h (R/W) = WAIT0 active high (high means data invalid)

Can you also confirm the WAIT signal shown in the waveform is WAIT0?

WAITPINSELECT is chosen in GPMC_CONFIG1_n

For my reference, can you share the waveform of the asynch write that is working?

Regards,
Mark

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AM3358: GPMC can not read correct data from FPGA