[Iverilog-devel] Assigning 6-bit databus to 6 bits of a register

[Nicholas K. <n....@us...>]

Hello--

I've been writing some code to model the collection of data from 6 
serial SPI ADCs.  The 6 ADCs are all being read at the same time.  Each 
bit is collected by a separate pin of the FPGA, and is an input into a 
module:

input [5:0] miso;

I've created a register "adc_data" which is also an output of the module:

output [107:0] adc_data;
reg [107:0] adc_data = 0;

I would like to assign the 6-bit miso input to a 6-bit range of the 
adc_data register.  Here is a code snippet from an always block within 
the module:


                   // always block triggered on the posedge of clk
                    if(ccc >= 1)
                    {
                        case(ccc)
                             1: adc_data[5:0] <= miso;
                             2: adc_data[11:6] <= miso;
                             3: adc_data[17:12] <= miso;
                             4: adc_data[23:18] <= miso;
                             5: adc_data[29:24] <= miso;
                             6: adc_data[35:30] <= miso;
                             7: adc_data[41:36] <= miso;
                             8: adc_data[47:42] <= miso;
                             9: adc_data[53:48] <= miso;
                             10: adc_data[59:54] <= miso;
                             11: adc_data[65:60] <= miso;
                             12: adc_data[71:66] <= miso;
                             13: adc_data[77:72] <= miso;
                             14: adc_data[83:78] <= miso;
                             15: adc_data[89:84] <= miso;
                             16: adc_data[95:90] <= miso;
                             17: adc_data[101:96] <= miso;
                             18: adc_data[107:102] <= miso;
                        endcase
 
                    }


However, this code is not valid, and the error that I receive from 
Icarus is:

adc.v:120: syntax error
adc.v:121: Syntax in assignment statement l-value.
adc.v:122: syntax error
adc.v:122: Syntax in assignment statement l-value.
adc.v:123: syntax error
adc.v:123: Syntax in assignment statement l-value.
adc.v:124: syntax error
adc.v:124: Syntax in assignment statement l-value.
adc.v:125: syntax error
adc.v:125: Syntax in assignment statement l-value.
adc.v:126: syntax error
adc.v:126: Syntax in assignment statement l-value.
adc.v:127: syntax error
adc.v:127: Syntax in assignment statement l-value.
adc.v:128: syntax error
adc.v:128: Syntax in assignment statement l-value.
adc.v:129: syntax error
adc.v:129: Syntax in assignment statement l-value.
adc.v:130: syntax error
adc.v:130: Syntax in assignment statement l-value.
adc.v:131: syntax error
adc.v:131: Syntax in assignment statement l-value.
adc.v:132: syntax error
adc.v:132: Syntax in assignment statement l-value.
adc.v:133: syntax error
adc.v:133: Syntax in assignment statement l-value.
adc.v:134: syntax error
adc.v:134: Syntax in assignment statement l-value.
adc.v:135: syntax error
adc.v:135: Syntax in assignment statement l-value.
adc.v:136: syntax error
adc.v:136: Syntax in assignment statement l-value.
adc.v:137: syntax error
adc.v:137: Syntax in assignment statement l-value.
adc.v:138: syntax error
adc.v:138: Syntax in assignment statement l-value.
adc.v:139: syntax error
adc.v:147: Syntax in assignment statement l-value.

What might I be able to do to modify my code so that "miso" is assigned 
to a 6-bit range of "adc_data"?  I have tried this alternate code:

                    if(ccc >= 1)
                    {
                        if(ccc == 1)     adc_data[5:0] <= miso;
                        if(ccc == 2)     adc_data[11:6] <= miso;
                        if(ccc == 3)     adc_data[17:12] <= miso;
                        if(ccc == 4)     adc_data[23:18] <= miso;
                        if(ccc == 5)     adc_data[29:24] <= miso;
                        if(ccc == 6)     adc_data[35:30] <= miso;
                        if(ccc == 7)     adc_data[41:36] <= miso;
                        if(ccc == 8)     adc_data[47:42] <= miso;
                        if(ccc == 9)     adc_data[53:48] <= miso;
                        if(ccc == 10)     adc_data[59:54] <= miso;
                        if(ccc == 11)     adc_data[65:60] <= miso;
                        if(ccc == 12)     adc_data[71:66] <= miso;
                        if(ccc == 13)     adc_data[77:72] <= miso;
                        if(ccc == 14)     adc_data[83:78] <= miso;
                        if(ccc == 15)     adc_data[89:84] <= miso;
                        if(ccc == 16)     adc_data[95:90] <= miso;
                        if(ccc == 17)     adc_data[101:96] <= miso;
                        if(ccc == 18)     adc_data[107:102] <= miso;
                    }


However,  I still receive errors:

adc.v:119: syntax error
adc.v:119: Syntax in assignment statement l-value.
adc.v:137: syntax error
adc.v:142: Syntax in assignment statement l-value.


Thank you,

Nicholas