[Open SoC Debug] Queries Regarding GSoC and Open SoC

Philipp Wagner philipp.wagner at tum.de
Mon Mar 12 09:26:23 CET 2018


On 03/12/2018 07:07 AM, Anant Sharma wrote:
> So here is what the problem is, the ports i mentioned above are 
> instantiated to
> mor1kx as the parameters of the 'du_'s you mentioned and given is a 
> sceenshot
> that tells me that I am receiving nothing in those parameters. I know 
> the changes
> I have to make, but I need to know the current program counter to set 
> breakpoints
> right?
> 
>  >> input         dbg_stall_i, // External Stall Input
>  >> input         dbg_ewt_i, // External Watchpoint Trigger Input
>  >> output [3:0]  dbg_lss_o, // External Load/Store Unit Status
>  >> output [1:0]  dbg_is_o, // External Insn Fetch Status
>  >> output [10:0] dbg_wp_o, // Watchpoints Outputs
>  >> output        dbg_bp_o, // Breakpoint Output
>  >> input         dbg_stb_i, // External Address/Data Strobe
>  >> input         dbg_we_i, // External Write Enable
>  >> input [31:0]  dbg_adr_i, // External Address Input
>  >> input [31:0]  dbg_dat_i, // External Data Input
>  >> output [31:0] dbg_dat_o, // External Data Output
>  >> output        dbg_ack_o, // External Data Acknowledge (not WB 
> compatible)
>  >
>  >
>  > These signals are the read/write ports for the debug registers.
> 
> Well as gtkwave suggests, these ports do not receive any information 
> throughout
> the execution of the program. That is the part I was confused about in 
> my previous
> email since I wasn't able to receive any data from anywhere.

As long as you don't drive the bus you will not see any activity there. 
As this is a rather fundamental question, please pick up any digital 
design textbook on how to interact with a bus.

Best,

Philipp


More information about the OpenSoCDebug mailing list