Linux/AM3715: McSPI TX remains full

ranchu

Guru 20755 points

Part Number: AM3715

Tool/software: Linux

Hello,

I am using mcspi ,

I have started testing it, but for some unknown reason, I get that mcspi tx remains full.

In MCSPI_CHxSTAT register txs bit remains 1 , after sending one byte in mcspi.

I use mcspi2, and check register 0x4809a030 (MCSPI_CHxSTAT) :

0x4809a000:
0x4809a000: 0021 0000 0000 0000
0x4809a010: 0015 0001 0005 0000
0x4809a020: 0000 0000 0001 1c3d9
0x4809a030: 0007 0000 0000 0000

Is there any reason why the byte is not being send ?

MCSPI #2 is configured as master.

Regards,

Ran

0 Biser Gatchev-XID over 8 years ago

Hi,

We do not have baremetal support for AM37x devices. You can look at the SPI software in the AM335x Starterware package for reference:
software-dl.ti.com/.../index_FDS.html
processors.wiki.ti.com/.../StarterWare_02.00.01.01_User_Guide
processors.wiki.ti.com/.../StarterWare_McSPI

0 ranchu over 8 years ago in reply to Biser Gatchev-XID

Guru 20755 points

Hello Biser,

The question is relevant for u-boot only.

But it is more a question of understanding the HW datasheet.

I try to understand what HW reason for mcspi to stay in TX full, (as if it doesn't transmit the waiting byte).

Is it a cloack issue ? or maybe pinmux ?

Thank you,

Ran

0 melissaw over 8 years ago in reply to ranchu

Hi Ran,

It sounds like this register is behaving as expected.

According to the AM3715 TRM (excerpt below), the TXS bit is set to 1 when the Register is Empty.

Regards,

Melissa

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