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// CAS Latency
cas_latency = addr[6:4];
read_latency = cas_latency + additive_latency;
write_latency = read_latency - 1;
if ((cas_latency >= CL_MIN) && (cas_latency <= CL_MAX)) begin
if (DEBUG) $display ("%m: at time %t INFO: %s %d CAS Latency = %d", $time, cmd_string[cmd], bank, cas_latency);
end else begin
$display ("%m: at time %t ERROR: %s %d Illegal CAS Latency = %d", $time, cmd_string[cmd], bank, cas_latency);
end
// Test Mode
if (!addr[7]) begin
if (DEBUG) $display ("%m: at time %t INFO: %s %d Test Mode = Normal", $time, cmd_string[cmd], bank);
end else begin
$display ("%m: at time %t ERROR: %s %d Illegal Test Mode = %d", $time, cmd_string[cmd], bank, addr[7]);
end
// DLL Reset
dll_reset = addr[8];
if (!dll_reset) begin
if (DEBUG) $display ("%m: at time %t INFO: %s %d DLL Reset = Normal", $time, cmd_string[cmd], bank);
end else if (dll_reset) begin
if (DEBUG) $display ("%m: at time %t INFO: %s %d DLL Reset = Reset DLL", $time, cmd_string[cmd], bank);
dll_locked = 0;
ck_dll_reset <= ck_cntr;
end else begin
$display ("%m: at time %t ERROR: %s %d Illegal DLL Reset = %d", $time, cmd_string[cmd], bank, dll_reset);
end
// Write Recovery
write_recovery = addr[11:9] + 1;
if ((write_recovery >= WR_MIN) && (write_recovery <= WR_MAX)) begin
if (DEBUG) $display ("%m: at time %t INFO: %s %d Write Recovery = %d", $time, cmd_string[cmd], bank, write_recovery);
end else begin
$display ("%m: at time %t ERROR: %s %d Illegal Write Recovery = %d", $time, cmd_string[cmd], bank, write_recovery);
end
// Power Down Mode
low_power = addr[12];
if (!low_power) begin
if (DEBUG) $display ("%m: at time %t INFO: %s %d Power Down Mode = Fast Exit", $time, cmd_string[cmd], bank);
end else if (low_power) begin
if (DEBUG) $display ("%m: at time %t INFO: %s %d Power Down Mode = Slow Exit", $time, cmd_string[cmd], bank);
end else begin
$display ("%m: at time %t ERROR: %s %d Illegal Power Down Mode = %d", $time, cmd_string[cmd], bank, low_power);
end
end
1 : begin
// DLL Enable
dll_en = !addr[0];
if (!dll_en) begin
if (DEBUG) $display ("%m: at time %t INFO: %s %d DLL Enable = Disabled", $time, cmd_string[cmd], bank);
end else if (dll_en) begin
if (DEBUG) $display ("%m: at time %t INFO: %s %d DLL Enable = Enabled", $time, cmd_string[cmd], bank);
end else begin
$display ("%m: at time %t ERROR: %s %d Illegal DLL Enable = %d", $time, cmd_string[cmd], bank, dll_en);
end
// Output Drive Strength
if (!addr[1]) begin
if (DEBUG) $display ("%m: at time %t INFO: %s %d Output Drive Strength = Full", $time, cmd_string[cmd], bank);
end else if (addr[1]) begin
if (DEBUG) $display ("%m: at time %t INFO: %s %d Output Drive Strength = Reduced", $time, cmd_string[cmd], bank);
end else begin
$display ("%m: at time %t ERROR: %s %d Illegal Output Drive Strength = %d", $time, cmd_string[cmd], bank, addr[1]);
end
// ODT Rtt
odt_rtt = {addr[6], addr[2]};
if (odt_rtt == 2'b00) begin
if (DEBUG) $display ("%m: at time %t INFO: %s %d ODT Rtt = Disabled", $time, cmd_string[cmd], bank);
odt_en = 0;
end else if (odt_rtt == 2'b01) begin
if (DEBUG) $display ("%m: at time %t INFO: %s %d ODT Rtt = 75 Ohm", $time, cmd_string[cmd], bank);
odt_en = 1;
ck_odt_en <= ck_cntr;
end else if (odt_rtt == 2'b10) begin
if (DEBUG) $display ("%m: at time %t INFO: %s %d ODT Rtt = 150 Ohm", $time, cmd_string[cmd], bank);
odt_en = 1;
ck_odt_en <= ck_cntr;
end else begin
$display ("%m: at time %t ERROR: %s %d Illegal ODT Rtt = %d", $time, cmd_string[cmd], bank, odt_rtt);
odt_en = 0;
end
// Additive Latency
additive_latency = addr[5:3];
read_latency = cas_latency + additive_latency;
write_latency = read_latency - 1;
if ((additive_latency >= AL_MIN) && (additive_latency <= AL_MAX)) begin
if (DEBUG) $display ("%m: at time %t INFO: %s %d Additive Latency = %d", $time, cmd_string[cmd], bank, additive_latency);
end else begin
$display ("%m: at time %t ERROR: %s %d Illegal Additive Latency = %d", $time, cmd_string[cmd], bank, additive_latency);
end
// OCD Program
ocd = addr[9:7];
if (ocd == 3'b000) begin
if (DEBUG) $display ("%m: at time %t INFO: %s %d OCD Program = OCD Exit", $time, cmd_string[cmd], bank);
end else if (ocd == 3'b111) begin
if (DEBUG) $display ("%m: at time %t INFO: %s %d OCD Program = OCD Default", $time, cmd_string[cmd], bank);
end else begin
$display ("%m: at time %t ERROR: %s %d Illegal OCD Program = %b", $time, cmd_string[cmd], bank, ocd);
end
// DQS_N Enable
dqs_n_en = !addr[10];
if (!dqs_n_en) begin
if (DEBUG) $display ("%m: at time %t INFO: %s %d DQS_N Enable = Disabled", $time, cmd_string[cmd], bank);
end else if (dqs_n_en) begin
if (DEBUG) $display ("%m: at time %t INFO: %s %d DQS_N Enable = Enabled", $time, cmd_string[cmd], bank);
end else begin
$display ("%m: at time %t ERROR: %s %d Illegal DQS_N Enable = %d", $time, cmd_string[cmd], bank, dqs_n_en);
end
// RDQS Enable
rdqs_en = addr[11];
if (!rdqs_en) begin
if (DEBUG) $display ("%m: at time %t INFO: %s %d RDQS Enable = Disabled", $time, cmd_string[cmd], bank);
end else if (rdqs_en) begin
`ifdef x8
if (DEBUG) $display ("%m: at time %t INFO: %s %d RDQS Enable = Enabled", $time, cmd_string[cmd], bank);
`else
$display ("%m: at time %t ERROR: %s %d Illegal RDQS Enable. RDQS only exists on a x8 part", $time, cmd_string[cmd], bank);
`endif
end else begin
$display ("%m: at time %t ERROR: %s %d Illegal RDQS Enable = %d", $time, cmd_string[cmd], bank, rdqs_en);
end
// Output Enable
out_en = !addr[12];
if (!out_en) begin
if (DEBUG) $display ("%m: at time %t INFO: %s %d Output Enable = Disabled", $time, cmd_string[cmd], bank);
end else if (out_en) begin
if (DEBUG) $display ("%m: at time %t INFO: %s %d Output Enable = Enabled", $time, cmd_string[cmd], bank);
end else begin
$display ("%m: at time %t ERROR: %s %d Illegal Output Enable = %d", $time, cmd_string[cmd], bank, out_en);
end
end
2, 3 : begin
if (addr !== 0) begin
$display ("%m: at time %t ERROR: %s %d Illegal value. Reserved bits must be programmed to zero", $time, cmd_string[cmd], bank);
end
end
endcase
init_mode_reg[bank] = 1;
ck_load_mode <= ck_cntr;
end
end
REFRESH : begin
if (|active_bank) begin
$display ("%m: at time %t ERROR: %s Failure. All banks must be Precharged.", $time, cmd_string[cmd]);
if (STOP_ON_ERROR) $stop(0);
end else begin
if (DEBUG) $display ("%m: at time %t INFO: %s", $time, cmd_string[cmd]);
er_trfc_max = 0;
ref_cntr = ref_cntr + 1;
tm_refresh <= $time;
end
end
PRECHARGE : begin
// tRPA timing applies when the PRECHARGE (ALL) command is issued, regardless of
// the number of banks already open or closed.
if (addr[AP] && (`BANKS == 8)) begin
precharge_all = 1'b1;
end
// PRECHARGE command will be treated as a NOP if there is no open row in that bank (idle state),
// or if the previously open row is already in the process of precharging
if (|active_bank) begin
for (i=0; i<`BANKS; i=i+1) begin
if (active_bank[i]) begin
if (addr[AP] || (i == bank)) begin
for (j=0; j<NOP; j=j+1) begin
chk_err(1'b0, i, j, cmd);
chk_err(1'b1, i, j, cmd);
end
chk_err(1'b0, i, PWR_DOWN, cmd);
chk_err(1'b0, i, SELF_REF, cmd);
if (auto_precharge_bank[i]) begin
$display ("%m: at time %t ERROR: %s Failure. Auto Precharge is scheduled to bank %d.", $time, cmd_string[cmd], i);
if (STOP_ON_ERROR) $stop(0);
end else begin
if (DEBUG) $display ("%m: at time %t INFO: %s bank %d", $time, cmd_string[cmd], i);
active_bank[i] = 1'b0;
tm_bank_precharge[i] <= $time;
tm_precharge <= $time;
end
end
end
end
end
end
ACTIVATE : begin
if (`BANKS == 8) begin
tfaw_cntr = 0;
for (i=0; i<`BANKS; i=i+1) begin
if ($time - tm_bank_activate[i] < TFAW) begin
tfaw_cntr = tfaw_cntr + 1;
end
end
if (tfaw_cntr > 3) begin
$display ("%m: at time %t ERROR: tFAW violation during %s to bank %d", $time, cmd_string[cmd], bank);
end
end
if (!init_done) begin
$display ("%m: at time %t ERROR: %s Failure. Initialization sequence is not complete.", $time, cmd_string[cmd]);
if (STOP_ON_ERROR) $stop(0);
end else if (active_bank[bank]) begin
$display ("%m: at time %t ERROR: %s Failure. Bank %d must be Precharged.", $time, cmd_string[cmd], bank);
if (STOP_ON_ERROR) $stop(0);
end else begin
if (addr >= 1<<ROW_BITS) begin
$display ("%m: at time %t WARNING: row = %h does not exist. Maximum row = %h", $time, addr, (1<<ROW_BITS)-1);
end
if (DEBUG) $display ("%m: at time %t INFO: %s bank %d row %h", $time, cmd_string[cmd], bank, addr);
active_bank[bank] = 1'b1;
active_row[bank] = addr;
tm_activate <= $time;
tm_bank_activate[bank] <= $time;
end
end
WRITE : begin
// allow for dummy write during init sequence
if (!init_done && (ref_cntr < 2)) begin
$display ("%m: at time %t ERROR: %s Failure. Initialization sequence is not complete.", $time, cmd_string[cmd]);
if (STOP_ON_ERROR) $stop(0);
end else if (!active_bank[bank]) begin
$display ("%m: at time %t ERROR: %s Failure. Bank %d must be Activated.", $time, cmd_string[cmd], bank);
if (STOP_ON_ERROR) $stop(0);
end else if (auto_precharge_bank[bank]) begin
$display ("%m: at time %t ERROR: %s Failure. Auto Precharge is scheduled to bank %d.", $time, cmd_string[cmd], bank);
if (STOP_ON_ERROR) $stop(0);
end else if ((ck_cntr - ck_write < burst_length/2) && (ck_cntr - ck_write)%2) begin
$display ("%m: at time %t ERROR: %s Failure. Illegal burst interruption.", $time, cmd_string[cmd]);
if (STOP_ON_ERROR) $stop(0);
end else begin
if (addr[AP]) begin
auto_precharge_bank[bank] = 1'b1;
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