[mem_bkdr_if] Rework write8 function to allow more memory widths
This patch changes write8 to dispatch on the integrity type and then
the memory width and then simplifies the "no integrity" and "parity"
paths significantly, generalising them to allow arbitrary memory
widths.
Signed-off-by: Rupert Swarbrick <rswarbrick@lowrisc.org>
diff --git a/hw/dv/sv/mem_bkdr_if/mem_bkdr_if.sv b/hw/dv/sv/mem_bkdr_if/mem_bkdr_if.sv
index 7ea307c..208808a 100644
--- a/hw/dv/sv/mem_bkdr_if/mem_bkdr_if.sv
+++ b/hw/dv/sv/mem_bkdr_if/mem_bkdr_if.sv
@@ -205,128 +205,123 @@
return 'x;
endfunction
+ // Internal function to write a single byte to the memory (updating no check bits)
+ function automatic void _write8_raw(int word_idx, int byte_idx, bit [7:0] data);
+ logic [MAX_MEM_WIDTH-1:0] rw_data = `MEM_ARR_PATH_SLICE[word_idx];
+ rw_data[byte_idx * 8 +: 8] = data;
+ `MEM_ARR_PATH_SLICE[word_idx] = rw_data;
+ endfunction
+
+ // Internal function to write a single byte to the memory, correctly updating its parity bit.
+ function automatic void _write8_parity(int word_idx,
+ int byte_idx,
+ bit [7:0] data,
+ int inject_num_errors);
+ logic [MAX_MEM_WIDTH-1:0] rw_data = `MEM_ARR_PATH_SLICE[word_idx];
+
+ // Lane is the 9-bit "byte" that should be written into the word.
+ bit [MEM_BYTE_MSB-1:0] lane = {~(^data), data};
+
+ // TODO: check with designer, current testbench only support 1 bit parity error.
+ `DV_CHECK_LE(inject_num_errors, 1, "Parity only supports 1 bit error", , path)
+
+ // Note that if memory parity checks are enabled,
+ // we have to write the correct parity bit as well.
+ // Odd parity is used, rather than even parity checking.
+ //
+ // TODO: odd/even parity checks could be made configurable.
+ if (inject_num_errors) begin
+ lane ^= (1 << $urandom_range(0, MEM_BYTE_MSB - 1));
+ end
+
+ // Inject the lane that we've written into the word and then write the word back to the memory.
+ rw_data[byte_idx * MEM_BYTE_MSB +: MEM_BYTE_MSB] = lane;
+ `MEM_ARR_PATH_SLICE[word_idx] = rw_data;
+ endfunction
+
+ // Internal function to write a single byte to the memory, correctly updating the ECC bits.
+ function automatic void _write8_ecc(int word_idx,
+ int byte_idx,
+ bit [7:0] data,
+ int inject_num_errors);
+ bit [MAX_MEM_WIDTH-1:0] rw_data = `MEM_ARR_PATH_SLICE[word_idx];
+ rw_data[byte_idx * 8 +: 8] = data;
+
+ // Check the requested number of injected ECC errors is possible.
+ `DV_CHECK_LE(inject_num_errors, MAX_MEM_WIDTH,
+ $sformatf("Max %0d bits to inject ECC error", MAX_MEM_WIDTH), , path)
+
+ case (mem_bytes_per_word)
+ 2: begin
+ case (MEM_ECC)
+ Secded_22_16: begin
+ rw_data = prim_secded_22_16_enc(rw_data[ECC_DATA_WIDTH-1:0]);
+ end
+ SecdedHamming_22_16: begin
+ rw_data = prim_secded_hamming_22_16_enc(rw_data[ECC_DATA_WIDTH-1:0]);
+ end
+ default: begin
+ `uvm_error(path,
+ $sformatf("MEM_ECC %0s is unsupported at mem_width[%0d]", MEM_ECC, mem_width))
+ end
+ endcase
+ end
+ 4: begin
+ case (MEM_ECC)
+ Secded_39_32: begin
+ rw_data = prim_secded_39_32_enc(rw_data[ECC_DATA_WIDTH-1:0]);
+ end
+ SecdedHamming_39_32: begin
+ rw_data = prim_secded_hamming_39_32_enc(rw_data[ECC_DATA_WIDTH-1:0]);
+ end
+ default: begin
+ `uvm_error(path,
+ $sformatf("MEM_ECC %0s is unsupported at mem_width[%0d]", MEM_ECC, mem_width))
+ end
+ endcase
+ end
+ 8: begin
+ case (MEM_ECC)
+ Secded_72_64: begin
+ rw_data = prim_secded_72_64_enc(rw_data[ECC_DATA_WIDTH-1:0]);
+ end
+ SecdedHamming_72_64: begin
+ rw_data = prim_secded_hamming_72_64_enc(rw_data[ECC_DATA_WIDTH-1:0]);
+ end
+ default: begin
+ `uvm_error(path,
+ $sformatf("MEM_ECC %0s is unsupported at mem_width[%0d]", MEM_ECC, mem_width))
+ end
+ endcase
+ end
+ default: begin
+ `uvm_error(path, $sformatf("ECC is not supported at mem_width[%0d]", mem_width))
+ end
+ endcase
+
+ if (inject_num_errors) rw_data = inject_errors(rw_data, inject_num_errors);
+
+ `MEM_ARR_PATH_SLICE[word_idx] = rw_data;
+ endfunction
+
function automatic void write8(input bit [bus_params_pkg::BUS_AW-1:0] addr,
input bit [7:0] data,
input int inject_num_errors = 0);
- if (is_addr_valid(addr)) begin
- int mem_index = addr >> mem_addr_lsb;
- bit [MAX_MEM_WIDTH-1:0] rw_data = `MEM_ARR_PATH_SLICE[mem_index];
+ int unsigned word_idx = addr >> mem_addr_lsb;
+ int unsigned byte_idx = addr - (word_idx << mem_addr_lsb);
- // Prepare corrupted data if an parity error injection is requested.
- //
- // We want to randomly inject errors into the parity bits themselves for better error
- // coverage.
- int idx_to_corrupt = $urandom_range(0, MEM_BYTE_MSB - 1);
+ if (!is_addr_valid(addr)) begin
+ `uvm_error(path, $sformatf("Address 0x%0h is not a valid address", addr))
+ end
- bit [MEM_BYTE_MSB-1:0] corrupted_data;
-
- // If inject ECC error, check the number of injected ecc_err is available.
- if (MEM_ECC != SecdedNone) begin
- `DV_CHECK_LE(inject_num_errors, MAX_MEM_WIDTH,
- $sformatf("Max %0d bits to inject ECC error", MAX_MEM_WIDTH), , path)
- end
-
- // TODO: check with designer, current testbench only support 1 bit parity error.
- if (MEM_PARITY) begin
- `DV_CHECK_LE(inject_num_errors, 1, "Parity only support 1 bit error", , path)
- end
-
- // Note that if memory parity checks are enabled,
- // we have to write the correct parity bit as well.
- // Odd parity is used, rather than even parity checking.
- //
- // TODO: odd/even parity checks could be made configurable.
- case (mem_bytes_per_word)
- // ECC is unavailable if only 1 byte in each memory word
- 1: begin
- rw_data[0 +: 8] = data;
- if (MEM_PARITY) begin
- rw_data[0 + 8] = ~(^data);
- if (inject_num_errors) begin
- corrupted_data = rw_data[0 +: MEM_BYTE_MSB];
- corrupted_data[idx_to_corrupt] = !corrupted_data[idx_to_corrupt];
- rw_data[0 +: MEM_BYTE_MSB] = corrupted_data;
- end
- end
- end
- 2: begin
- rw_data[addr[0] * MEM_BYTE_MSB +: 8] = data;
- if (MEM_PARITY) begin
- rw_data[addr[0] * MEM_BYTE_MSB + 8] = ~(^data);
- if (inject_num_errors) begin
- corrupted_data = rw_data[addr[0] * MEM_BYTE_MSB +: MEM_BYTE_MSB];
- corrupted_data[idx_to_corrupt] = !corrupted_data[idx_to_corrupt];
- rw_data[addr[0] * MEM_BYTE_MSB +: MEM_BYTE_MSB] = corrupted_data;
- end
- end else if (MEM_ECC != SecdedNone) begin
- case (MEM_ECC)
- Secded_22_16: begin
- rw_data = prim_secded_22_16_enc(rw_data[ECC_DATA_WIDTH-1:0]);
- end
- SecdedHamming_22_16: begin
- rw_data = prim_secded_hamming_22_16_enc(rw_data[ECC_DATA_WIDTH-1:0]);
- end
- default: begin
- `uvm_error(path,
- $sformatf("MEM_ECC %0s is unsupported at mem_width[%0d]", MEM_ECC, mem_width))
- end
- endcase
- if (inject_num_errors) rw_data = inject_errors(rw_data, inject_num_errors);
- end
- end
- 4: begin
- rw_data[addr[1:0] * MEM_BYTE_MSB +: 8] = data;
- if (MEM_PARITY) begin
- rw_data[addr[1:0] * MEM_BYTE_MSB + 8] = ~(^data);
- if (inject_num_errors) begin
- corrupted_data = rw_data[addr[1:0] * MEM_BYTE_MSB +: MEM_BYTE_MSB];
- corrupted_data[idx_to_corrupt] = !corrupted_data[idx_to_corrupt];
- rw_data[addr[1:0] * MEM_BYTE_MSB +: MEM_BYTE_MSB] = corrupted_data;
- end
- end else if (MEM_ECC != SecdedNone) begin
- case (MEM_ECC)
- Secded_39_32: begin
- rw_data = prim_secded_39_32_enc(rw_data[ECC_DATA_WIDTH-1:0]);
- end
- SecdedHamming_39_32: begin
- rw_data = prim_secded_hamming_39_32_enc(rw_data[ECC_DATA_WIDTH-1:0]);
- end
- default: begin
- `uvm_error(path,
- $sformatf("MEM_ECC %0s is unsupported at mem_width[%0d]", MEM_ECC, mem_width))
- end
- endcase
- if (inject_num_errors) rw_data = inject_errors(rw_data, inject_num_errors);
- end
- end
- 8: begin
- rw_data[addr[2:0] * MEM_BYTE_MSB +: 8] = data;
- if (MEM_PARITY) begin
- rw_data[addr[2:0] * MEM_BYTE_MSB + 8] = ~(^data);
- if (inject_num_errors) begin
- corrupted_data = rw_data[addr[2:0] * MEM_BYTE_MSB +: MEM_BYTE_MSB];
- corrupted_data[idx_to_corrupt] = !corrupted_data[idx_to_corrupt];
- rw_data[addr[2:0] * MEM_BYTE_MSB +: MEM_BYTE_MSB] = corrupted_data;
- end
- end else if (MEM_ECC != SecdedNone) begin
- case (MEM_ECC)
- Secded_72_64: begin
- rw_data = prim_secded_72_64_enc(rw_data[ECC_DATA_WIDTH-1:0]);
- end
- SecdedHamming_72_64: begin
- rw_data = prim_secded_hamming_72_64_enc(rw_data[ECC_DATA_WIDTH-1:0]);
- end
- default: begin
- `uvm_error(path,
- $sformatf("MEM_ECC %0s is unsupported at mem_width[%0d]", MEM_ECC, mem_width))
- end
- endcase
- if (inject_num_errors) rw_data = inject_errors(rw_data, inject_num_errors);
- end
- end
- default: ;
- endcase
- `MEM_ARR_PATH_SLICE[mem_index] = rw_data;
+ if (MEM_ECC != SecdedNone) begin
+ _write8_ecc(word_idx, byte_idx, data, inject_num_errors);
+ end else if (MEM_PARITY) begin
+ _write8_parity(word_idx, byte_idx, data, inject_num_errors);
+ end else begin
+ `DV_CHECK_FATAL(inject_num_errors == 0,
+ "Can't inject errors with no integrity protection.", path)
+ _write8_raw(word_idx, byte_idx, data);
end
endfunction
