Unsupported LHS tristate construct: ARRAYSEL
I am wondering what this actually means, I was under the impression that this is legal SystemVerilog. I am trying to instantiate the IO padring for my GPIOs using a parameter.
The error I get when I do this is:
%Error: <path><line>: Unsupported LHS tristate construct: ARRAYSEL
module GPIO_iop #( parameter NumGPIOs = 4 ) ( inout p_gpio[NumGPIOs], input do_gpio[NumGPIOs], output di_gpio[NumGPIOs], input do_gpio_hiz[NumGPIOs] ); genvar i; generate for(i = 0; i < NumGPIOs; i = i+1) begin: Gen_gpio_0 IOBUF gpio ( .T(do_gpio_hiz[i]), .I(do_gpio[i]), .O(di_gpio[i]), .IO(p_gpio[i])); end endgenerate endmodule
I also tried doing something like this, but got the exact same error:
module GPIONGeneralPurposeIOs_216_iop #( parameter USERPARAM_NumGPIOs = 4 ) ( inout p_gpio[USERPARAM_NumGPIOs], input do_gpio[USERPARAM_NumGPIOs], output di_gpio[USERPARAM_NumGPIOs], input do_gpio_hiz[USERPARAM_NumGPIOs] ); IOBUF gpio[USERPARAM_NumGPIOs] ( .T(do_gpio_hiz), .I(do_gpio), .O(di_gpio), .IO(p_gpio)); endmodule
Am I doing something wrong, or is this a currently unsupported feature? If it is unsupported, how hard would it be to have it supported?
Thank you for your assistance in this matter.
#2 Updated by Rob Stoddard about 1 year ago
What I provided was a trifle example, as you probably know, I am writing software that generates RTL dynamically. Although I don't have an example of one, there is the chance the user will create a parameter-generated set of busses. Supposing the busses are 8 bits each, the user would have something like:
inout [7:0] p_busses [NumBusses];
of course I can do something like this, but it's a little more painful:
inout [8*NumBusses-1:0] p_busses;
I was just hoping to not have to do that.
#4 Updated by Wilson Snyder about 1 year ago
- Status changed from New to Confirmed
Due to how the code currently works supporting arrays will be painful, so is unlikely to be improved in the short term, unless you are willing to commit a patch.
Using packed arrays in some form is the recommended workaround in the meantime.
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