[otp_ctrl/lint] Update range comparisons

This ensures we are not inserting range comparisons that can
never be false (which the linter complained about).

Signed-off-by: Michael Schaffner <[email protected]>

hw/ip/otp_ctrl/rtl/otp_ctrl.sv

@@ -231,8 +231,12 @@ module otp_ctrl
  for (genvar k = 0; k < NumPart; k++) begin : gen_part_sel
  localparam logic [OtpByteAddrWidth:0] PartEnd = (OtpByteAddrWidth+1)'(PartInfo[k].offset) +
  (OtpByteAddrWidth+1)'(PartInfo[k].size);
- assign tlul_part_sel_oh[k] = ({tlul_addr, 2'b00} >= PartInfo[k].offset) &
- ({1'b0, {tlul_addr, 2'b00}} < PartEnd);
+ if (PartInfo[k].offset == 0) begin : gen_zero_offset
+ assign tlul_part_sel_oh[k] = ({1'b0, {tlul_addr, 2'b00}} < PartEnd);
+ end else begin : gen_nonzero_offset
+ assign tlul_part_sel_oh[k] = ({tlul_addr, 2'b00} >= PartInfo[k].offset) &
+ ({1'b0, {tlul_addr, 2'b00}} < PartEnd);
+ end
  end
 
  `ASSERT(PartSelMustBeOnehot_A, $onehot0(tlul_part_sel_oh))

hw/ip/otp_ctrl/rtl/otp_ctrl_dai.sv

@@ -702,8 +702,13 @@ module otp_ctrl_dai
  // between OtpAddrWidth and OtpByteAddrWidth, so we know that we can slice safely here.
  localparam bit [OtpAddrWidth-1:0] DigestAddrLut = DigestAddrLutInt[OtpAddrWidth-1:0];
 
- assign part_sel_oh[k] = (dai_addr_i >= PartInfo[k].offset) &
- ({1'b0, dai_addr_i} < PartEndInt[OtpByteAddrWidth:0]);
+ if (PartInfo[k].offset == 0) begin : gen_zero_offset
+ assign part_sel_oh[k] = ({1'b0, dai_addr_i} < PartEndInt[OtpByteAddrWidth:0]);
+
+ end else begin : gen_nonzero_offset
+ assign part_sel_oh[k] = (dai_addr_i >= PartInfo[k].offset) &
+ ({1'b0, dai_addr_i} < PartEndInt[OtpByteAddrWidth:0]);
+ end
  assign digest_addr_lut[k] = DigestAddrLut;
  end
 

hw/ip/otp_ctrl/rtl/otp_ctrl_part_unbuf.sv

@@ -128,6 +128,7 @@ module otp_ctrl_part_unbuf
  logic digest_reg_en;
  logic ecc_err;
 
+ logic tlul_addr_in_range;
  logic [SwWindowAddrWidth-1:0] tlul_addr_d, tlul_addr_q;
 
  // This is only used to return bus errors when the FSM is in ErrorSt.
@@ -233,9 +234,7 @@ module otp_ctrl_part_unbuf
  ReadSt: begin
  init_done_o = 1'b1;
  // Double check the address range.
- if ({tlul_addr_q, 2'b00} >= Info.offset &&
- {1'b0, tlul_addr_q, 2'b00} < PartEnd &&
- mubi8_test_false_strict(access_o.read_lock)) begin
+ if (tlul_addr_in_range && mubi8_test_false_strict(access_o.read_lock)) begin
  otp_req_o = 1'b1;
  otp_addr_sel = DataAddrSel;
  if (otp_gnt_i) begin
@@ -325,6 +324,14 @@ module otp_ctrl_part_unbuf
  // Do not forward data in case of an error.
  assign tlul_rdata_o = (tlul_rvalid_o && tlul_rerror_o == '0) ? otp_rdata_i[31:0] : '0;
 
+ if (Info.offset == 0) begin : gen_zero_offset
+ assign tlul_addr_in_range = {1'b0, tlul_addr_q, 2'b00} < PartEnd;
+
+ end else begin : gen_nonzero_offset
+ assign tlul_addr_in_range = {tlul_addr_q, 2'b00} >= Info.offset &&
+ {1'b0, tlul_addr_q, 2'b00} < PartEnd;
+ end
+
  // Note that OTP works on halfword (16bit) addresses, hence need to
  // shift the addresses appropriately.
  logic [OtpByteAddrWidth-1:0] addr_calc;

hw/ip/otp_ctrl/rtl/otp_ctrl_scrmbl.sv

@@ -144,11 +144,12 @@ module otp_ctrl_scrmbl
  digest_iv_lut = '0;
 
  for (int k = 0; k < NumScrmblKeys; k++) begin
+ localparam logic [4:0] NumRounds = 5'(unsigned'(NumPresentRounds));
  otp_enc_key_lut[k] = rnd_cnst_key_anchor[k];
  // Due to the PRESENT key schedule, we have to step the key schedule function by
  // NumPresentRounds forwards to get the decryption key.
  otp_dec_key_lut[k] =
- prim_cipher_pkg::present_get_dec_key128(rnd_cnst_key_anchor[k], 5'(NumPresentRounds));
+ prim_cipher_pkg::present_get_dec_key128(rnd_cnst_key_anchor[k], NumRounds);
  end
 
  for (int k = 0; k < NumDigestSets; k++) begin