AM335x DCAN - Viewing message RAM from debugger

Vasili Galka

Hi,

1. The DCAN chapter in the AM335x TRM mentions Debug/Suspend mode:

"In debug/suspend mode, the message RAM will be memory mapped. This allows the external debug unit
to access the message RAM."

"The base address for DCAN0 RAM is 0x481C_D000 and DCAN1 RAM is 0x481D_1000."

How is this Debug/Suspend mode activated? Shall I just see the memory when I halt in CCS debugger? Because I observe just zeros at addresses starting from 0x481D_1000 (While if I activate the RDA mode I do see non zero values at these addresses).

2. I don't see the MsgVal bit neither in RDA nor in Debug/Suspend mode representation. Is that so and I shall observe it from the registers?

Best,
Vasili

over 12 years ago

0 Vasili Galka over 12 years ago

Expert 2690 points

Anyone?

0 Vidin Tsonev-XID over 12 years ago in reply to Vasili Galka

TI__Intellectual 1340 points

Hi Vasili,

Here some guide how to debug in CCS: http://processors.wiki.ti.com/index.php/Linux_Debug_in_CCSv5#Stop_Mode_Debug

About DCAN, the debug system has control registers for every peripheral module (including the two CANs). the registers are described in the latest TRM of AM335x on pg. 4732-4733. http://www.ti.com/lit/ug/spruh73i/spruh73i.pdf

In system debug it seems that you have to program the bits of Suspend Control Register for CAN

[3]Suspend_Default_Override

[0]SensCtrl

By default the settings of this register will NOT put CAN in debug mode and it will act as normal mode.

Can you try this settings?

Hope this helps.

Best regards,

Vidin

0 Vasili Galka over 12 years ago in reply to Vidin Tsonev-XID

Expert 2690 points

Hi Vidin,

I see. I had an older version of TRM which did not contain the Debug Subsystem documentation.
I'll try it.

Many thanks,
Vasili

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AM335x DCAN - Viewing message RAM from debugger