$readmemh had a limited width of 32 bits
module esp_test;
reg [155:0] data[0:393280];
initial begin
$readmemh("./datafile", data);
$write("0-%h\n",data[0]);
$write("1-%h\n",data[1]);
end
endmodule
/* datafile contents:
ffffffff_ffffffff_ffffffff_ffff_ffffffff_fff
d2010003_ba54865e_1d9260f2_0000_18100052_000
ffffffff_00000000_00000000_0000_00000000_000
*/
/* output:
0-0000000000000000000000000000000ffffffff
1-000000000000000000000000000000000052000
*/
/* expected:
0-fffffffffffffffffffffffffffffffffffffff
1-d2010003ba54865e1d9260f2000018100052000
*/