Concatenate arrays of bytes into one array

Question

Can I concatenate these byte banks:

logic [7:0] bank3[0 : 255];
logic [7:0] bank2[0 : 255];
logic [7:0] bank1[0 : 255];
logic [7:0] bank0[0 : 255];

To something like;

logic [32:0] address_array [0:255];
assign address_array = {bank3, bank2, bank1, bank0}; //!This is pseudocode!

The resulting array's size is 256 x 32bits.

Example:

If I want to read addresses 0x0,0x1,0x2,0x3 then I will access address_array[0]. Array's index should range from 0 to 255 and be 32bits wide.

Answer 1

No need to use generates a standard for loop will do:

reg [7:0] bank3[0 : 255];
reg [7:0] bank2[0 : 255];
reg [7:0] bank1[0 : 255];
reg [7:0] bank0[0 : 255];
reg [31:0] address_array[0:255];
integer i;

always @* begin
  for (i=0;i<256;i=i+1) begin
    address_array[i] = {bank3[i],bank2[i],bank1[i],bank0[i]};
  end
end

In SystemVerilog:

logic [7:0] bank3[0 : 255];
logic [7:0] bank2[0 : 255];
logic [7:0] bank1[0 : 255];
logic [7:0] bank0[0 : 255];
logic [31:0] address_array[0:255];

always_comb begin
  for (int i=0;i<256;i++) begin
    address_array[i] = {bank3[i],bank2[i],bank1[i],bank0[i]};
  end
end

As Greg has mention this could also utilise a foreach:

always_comb begin
  foreach ( bank_all[i] ) begin
    bank_all[i]= { bank_stack3[i], bank_stack2[i], bank_stack1[i], bank_stack0[i]};
  end
end

Solution 2

The question actually specified that instead of all of the banks to be 'stacked' vertically next to each other that bank0 would be reshaped to utilise the 32bit width. bank0 would be fully read before reaching bank1.

localparam DEPTH = 8;
logic [7:0] bank0[0 : DEPTH-1];
logic [7:0] bank1[0 : DEPTH-1];
logic [7:0] bank2[0 : DEPTH-1];
logic [7:0] bank3[0 : DEPTH-1];

logic [7:0]       bank_stack [(DEPTH*4) -1];
logic [(8*4)-1:0]   bank_all  [0 : DEPTH-1];

always_comb begin
  //First reshape vertically stack banks
  // IEEE 1800-2012 Section 11.4.14 Streaming operators
  {>>{bank_stack}} = {>>{bank0, bank1, bank2, bank3}};

  //Second reshape, flatten to 4 bytes wide.
   foreach ( bank_all[i] ) begin
    bank_all[i]= { bank_stack[i], bank_stack[i+1], bank_stack[i+2], bank_stack[i+3]};
  end
end

Short example on EDA Playground.

Thanks to Greg for the insight into IEEE 1800-2012 Section 11.4.14 Streaming operators.