AM4379 GPMC interfacing

jinu jacob

Other Parts Discussed in Thread: AM4379

Hi,

We are using am4379 IDK board. We need to connect a FPGA chip using GPMC memory interface.

For AM4379 device datasheet, it is mentioned that the GPMC memory base address starts from 0x00000000 location.it is also mentioned that first 1 MB address space cant be accessible.

We are using CS0. We need around 64MB GPMC memory. To achieve this,what are the values to be set in the following register field?

1) GPMC_CONFIG7_i[5-0] BASEADDRESS bit field.

2) GPMC_CONFIG7_i[11-8] MASKADDRESS bit field.

3) what is the start address that can be used as a first address to read from FPGA device?

Regards,

Jinu

over 9 years ago

0 Lalindra Jayatilleke over 9 years ago

TI__Mastermind 30365 points

Moving this thread to the Sitara forum.

0 Biser Gatchev-XID over 9 years ago

TI__Guru**** 393215 points

See section 9.1.3.3.8.1 from the AM437X TRM Rev. D.

0 jinu jacob over 9 years ago in reply to Biser Gatchev-XID

Expert 1185 points

Hi Biser,
Thanks for the reply. Can you please tell me whether the following settings are proper?

We need to assign 64 MB from GPMC memory for interfacing FPGA. For this, we connected FPGA to CS0 and we are planning to use the following settings in GPMC_CONFIG7_0 register.

Base Address(0-5)= 0x00000
Mask Address(11-8)= 0xC (64 MB CS)

1)With the above configuration will we able to access the 64 byte memory from location 0x00000401 (1025th byte since we cant use first 1 MB, effective start address is 0x00000401 )
2) in datasheet,it is mentioned that for base address field,16-M Bytes minimum granularity. what does this means?

Regards,
Jinu Jacob

0 Biser Gatchev-XID over 9 years ago in reply to jinu jacob

TI__Guru**** 393215 points

Yes, these values are correct.

1. 1MB offset is 0x100000, not 0x400
2. This means that smallest CS size is 16MB.

0 jinu jacob over 9 years ago in reply to Biser Gatchev-XID

Expert 1185 points

Thanks Biser.

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AM4379 GPMC interfacing