case(RESET_MODE)
"RISING": begin
- always @(posedge CLK or posedge RST) begin
- count <= count - 1'd1;
- if(count == 0)
- count <= COUNT_TO;
-
+ always @(posedge CLK, posedge RST) begin
if(RST)
- count <= 0;
+ count <= 0;
+ else begin
+ count <= count - 1'd1;
+ if(count == 0)
+ count <= COUNT_TO;
+ end
end
end
"FALLING": begin
- always @(posedge CLK or negedge RST) begin
- count <= count - 1'd1;
- if(count == 0)
- count <= COUNT_TO;
-
+ always @(posedge CLK, negedge RST) begin
if(!RST)
- count <= 0;
+ count <= 0;
+ else begin
+ count <= count - 1'd1;
+ if(count == 0)
+ count <= COUNT_TO;
+ end
end
end
"BOTH": begin
initial begin
- $display("Both-edge reset mode for GP_COUNT8 not implemented");
+ $display("Both-edge reset mode for GP_COUNT14 not implemented");
$finish;
end
end
"LEVEL": begin
- always @(posedge CLK or posedge RST) begin
- count <= count - 1'd1;
- if(count == 0)
- count <= COUNT_TO;
-
+ always @(posedge CLK, posedge RST) begin
if(RST)
- count <= 0;
+ count <= 0;
+
+ else begin
+ count <= count - 1'd1;
+ if(count == 0)
+ count <= COUNT_TO;
+ end
end
end
default: begin
initial begin
- $display("Invalid RESET_MODE on GP_COUNT8");
+ $display("Invalid RESET_MODE on GP_COUNT14");
$finish;
end
end
case(RESET_MODE)
"RISING": begin
- always @(posedge CLK or posedge RST) begin
-
- //Main counter
- if(KEEP) begin
- end
- else if(UP)
- count <= count + 1'd1;
- else
- count <= count - 1'd1;
-
- //Wrapping
- if(count == 0 && !UP)
- count <= COUNT_TO;
- if(count == 14'h3fff && UP)
- count <= COUNT_TO;
+ always @(posedge CLK, posedge RST) begin
//Resets
if(RST) begin
count <= COUNT_TO;
end
- end
- end
-
- "FALLING": begin
- always @(posedge CLK or negedge RST) begin
-
- //Main counter
- if(KEEP) begin
+ else if(KEEP) begin
end
- else if(UP)
+ else if(UP) begin
count <= count + 1'd1;
- else
+ if(count == 14'h3fff)
+ count <= COUNT_TO;
+ end
+ else begin
count <= count - 1'd1;
- //Wrapping
- if(count == 0 && !UP)
- count <= COUNT_TO;
- if(count == 14'h3fff && UP)
- count <= COUNT_TO;
+ if(count == 0)
+ count <= COUNT_TO;
+ end
+
+ end
+ end
+
+ "FALLING": begin
+ always @(posedge CLK, negedge RST) begin
//Resets
if(!RST) begin
count <= COUNT_TO;
end
+ else if(KEEP) begin
+ end
+ else if(UP) begin
+ count <= count + 1'd1;
+ if(count == 14'h3fff)
+ count <= COUNT_TO;
+ end
+ else begin
+ count <= count - 1'd1;
+
+ if(count == 0)
+ count <= COUNT_TO;
+ end
+
end
end
end
"LEVEL": begin
- always @(posedge CLK or posedge RST) begin
-
- //Main counter
- if(KEEP) begin
- end
- else if(UP)
- count <= count + 1'd1;
- else
- count <= count - 1'd1;
-
- //Wrapping
- if(count == 0 && !UP)
- count <= COUNT_TO;
- if(count == 14'h3fff && UP)
- count <= COUNT_TO;
+ always @(posedge CLK, posedge RST) begin
//Resets
if(RST) begin
count <= COUNT_TO;
end
+ else begin
+
+ if(KEEP) begin
+ end
+ else if(UP) begin
+ count <= count + 1'd1;
+ if(count == 14'h3fff)
+ count <= COUNT_TO;
+ end
+ else begin
+ count <= count - 1'd1;
+
+ if(count == 0)
+ count <= COUNT_TO;
+ end
+
+ end
+
end
end
case(RESET_MODE)
"RISING": begin
- always @(posedge CLK or posedge RST) begin
-
- //Main counter
- if(KEEP) begin
- end
- else if(UP)
- count <= count + 1'd1;
- else
- count <= count - 1'd1;
-
- //Wrapping
- if(count == 0 && !UP)
- count <= COUNT_TO;
- if(count == 8'hff && UP)
- count <= COUNT_TO;
+ always @(posedge CLK, posedge RST) begin
//Resets
if(RST) begin
count <= COUNT_TO;
end
- end
- end
-
- "FALLING": begin
- always @(posedge CLK or negedge RST) begin
-
//Main counter
- if(KEEP) begin
+ else if(KEEP) begin
end
- else if(UP)
+ else if(UP) begin
count <= count + 1'd1;
- else
+ if(count == 8'hff)
+ count <= COUNT_TO;
+ end
+ else begin
count <= count - 1'd1;
- //Wrapping
- if(count == 0 && !UP)
- count <= COUNT_TO;
- if(count == 8'hff && UP)
- count <= COUNT_TO;
+ if(count == 0)
+ count <= COUNT_TO;
+ end
+
+ end
+ end
+
+ "FALLING": begin
+ always @(posedge CLK, negedge RST) begin
//Resets
if(!RST) begin
count <= COUNT_TO;
end
+ //Main counter
+ else if(KEEP) begin
+ end
+ else if(UP) begin
+ count <= count + 1'd1;
+ if(count == 8'hff)
+ count <= COUNT_TO;
+ end
+ else begin
+ count <= count - 1'd1;
+
+ if(count == 0)
+ count <= COUNT_TO;
+ end
+
end
end
end
"LEVEL": begin
- always @(posedge CLK or posedge RST) begin
-
- //Main counter
- if(KEEP) begin
- end
- else if(UP)
- count <= count + 1'd1;
- else
- count <= count - 1'd1;
-
- //Wrapping
- if(count == 0 && !UP)
- count <= COUNT_TO;
- if(count == 8'hff && UP)
- count <= COUNT_TO;
+ always @(posedge CLK, posedge RST) begin
//Resets
if(RST) begin
count <= COUNT_TO;
end
+ else begin
+
+ if(KEEP) begin
+ end
+ else if(UP) begin
+ count <= count + 1'd1;
+ if(count == 8'hff)
+ count <= COUNT_TO;
+ end
+ else begin
+ count <= count - 1'd1;
+
+ if(count == 0)
+ count <= COUNT_TO;
+ end
+ end
+
end
end
//Combinatorially output underflow flag whenever we wrap low
always @(*) begin
OUT <= (count == 8'h0);
- OUT <= count;
+ POUT <= count;
end
//POR or SYSRST reset value is COUNT_TO. Datasheet is unclear but conversations w/ Silego confirm.
case(RESET_MODE)
"RISING": begin
- always @(posedge CLK or posedge RST) begin
- count <= count - 1'd1;
- if(count == 0)
- count <= COUNT_TO;
-
+ always @(posedge CLK, posedge RST) begin
if(RST)
count <= 0;
+ else begin
+ count <= count - 1'd1;
+ if(count == 0)
+ count <= COUNT_TO;
+ end
end
end
"FALLING": begin
- always @(posedge CLK or negedge RST) begin
- count <= count - 1'd1;
- if(count == 0)
- count <= COUNT_TO;
-
+ always @(posedge CLK, negedge RST) begin
if(!RST)
count <= 0;
+ else begin
+ count <= count - 1'd1;
+ if(count == 0)
+ count <= COUNT_TO;
+ end
end
end
end
"LEVEL": begin
- always @(posedge CLK or posedge RST) begin
- count <= count - 1'd1;
- if(count == 0)
- count <= COUNT_TO;
-
+ always @(posedge CLK, posedge RST) begin
if(RST)
count <= 0;
+
+ else begin
+ count <= count - 1'd1;
+ if(count == 0)
+ count <= COUNT_TO;
+ end
end
end
parameter PATTERN_DATA = 16'h0;
parameter PATTERN_LEN = 5'd16;
+ localparam COUNT_MAX = PATTERN_LEN - 1'h1;
+
reg[3:0] count = 0;
- always @(posedge CLK) begin
+ always @(posedge CLK, negedge nRST) begin
+
if(!nRST)
- OUT <= PATTERN_DATA[0];
+ count <= 0;
else begin
- count <= count + 1;
- OUT <= PATTERN_DATA[count];
-
- if( (count + 1) == PATTERN_LEN)
- count <= 0;
+ count <= count - 1'h1;
+ if(count == 0)
+ count <= COUNT_MAX;
end
end
+ always @(*)
+ OUT = PATTERN_DATA[count];
+
endmodule
module GP_SHREG(input nRST, input CLK, input IN, output OUTA, output OUTB);