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https://opencores.org/ocsvn/rtcclock/rtcclock/trunk
Subversion Repositories rtcclock
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/trunk/rtl/rtclight.v
0,0 → 1,410
/////////////////////////////////////////////////////////////////////////// |
// |
// Filename: rtclight.v |
// |
// Project: A Wishbone Controlled Real--time Clock Core |
// |
// Purpose: Implement a real time clock, including alarm, count--down |
// timer, stopwatch, variable time frequency, and more. |
// |
// This is a light-weight version of the RTC found in this directory. |
// Unlike the full RTC, this version does not support time hacks, seven |
// segment display outputs, or LED's. It is an RTC for an internal core |
// only. (That's how I was using it on one of my projects anyway ...) |
// |
// |
// Creator: Dan Gisselquist, Ph.D. |
// Gisselquist Tecnology, LLC |
// |
/////////////////////////////////////////////////////////////////////////// |
// |
// Copyright (C) 2015, Gisselquist Technology, LLC |
// |
// This program is free software (firmware): you can redistribute it and/or |
// modify it under the terms of the GNU General Public License as published |
// by the Free Software Foundation, either version 3 of the License, or (at |
// your option) any later version. |
// |
// This program is distributed in the hope that it will be useful, but WITHOUT |
// ANY WARRANTY; without even the implied warranty of MERCHANTIBILITY or |
// FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
// for more details. |
// |
// You should have received a copy of the GNU General Public License along |
// with this program. (It's in the $(ROOT)/doc directory. Run make with no |
// target there if the PDF file isn't present.) If not, see |
// <http://www.gnu.org/licenses/> for a copy. |
// |
// License: GPL, v3, as defined and found on www.gnu.org, |
// http://www.gnu.org/licenses/gpl.html |
// |
// |
/////////////////////////////////////////////////////////////////////////// |
module rtcclock(i_clk, |
// Wishbone interface |
i_wb_cyc, i_wb_stb, i_wb_we, i_wb_addr, i_wb_data, |
// o_wb_ack, o_wb_stb, o_wb_data, // no reads here |
// // Button inputs |
// i_btn, |
// Output registers |
o_data, // multiplexed based upon i_wb_addr |
// Output controls |
o_interrupt, |
// A once-per-day strobe on the last clock of the day |
o_ppd); |
input i_clk; |
input i_wb_cyc, i_wb_stb, i_wb_we; |
input [2:0] i_wb_addr; |
input [31:0] i_wb_data; |
// input i_btn; |
output reg [31:0] o_data; |
output wire o_interrupt, o_ppd; |
|
reg [31:0] clock, stopwatch, ckspeed; |
reg [25:0] timer; |
|
wire ck_sel, tm_sel, sw_sel, sp_sel, al_sel; |
assign ck_sel = ((i_wb_cyc)&&(i_wb_stb)&&(i_wb_addr[2:0]==3'b000)); |
assign tm_sel = ((i_wb_cyc)&&(i_wb_stb)&&(i_wb_addr[2:0]==3'b001)); |
assign sw_sel = ((i_wb_cyc)&&(i_wb_stb)&&(i_wb_addr[2:0]==3'b010)); |
assign al_sel = ((i_wb_cyc)&&(i_wb_stb)&&(i_wb_addr[2:0]==3'b011)); |
assign sp_sel = ((i_wb_cyc)&&(i_wb_stb)&&(i_wb_addr[2:0]==3'b100)); |
|
reg [39:0] ck_counter; |
reg ck_carry; |
always @(posedge i_clk) |
{ ck_carry, ck_counter } <= ck_counter + { 8'h00, ckspeed }; |
|
wire ck_pps; |
reg ck_prepps, ck_ppm, ck_pph, ck_ppd; |
reg [7:0] ck_sub; |
initial clock = 32'h00000000; |
assign ck_pps = (ck_carry)&&(ck_prepps); |
always @(posedge i_clk) |
begin |
if (ck_carry) |
ck_sub <= ck_sub + 8'h1; |
ck_prepps <= (ck_sub == 8'hff); |
|
if (ck_pps) |
begin // advance the seconds |
if (clock[3:0] >= 4'h9) |
clock[3:0] <= 4'h0; |
else |
clock[3:0] <= clock[3:0] + 4'h1; |
if (clock[7:0] >= 8'h59) |
clock[7:4] <= 4'h0; |
else if (clock[3:0] >= 4'h9) |
clock[7:4] <= clock[7:4] + 4'h1; |
end |
ck_ppm <= (clock[7:0] == 8'h59); |
|
if ((ck_pps)&&(ck_ppm)) |
begin // advance the minutes |
if (clock[11:8] >= 4'h9) |
clock[11:8] <= 4'h0; |
else |
clock[11:8] <= clock[11:8] + 4'h1; |
if (clock[15:8] >= 8'h59) |
clock[15:12] <= 4'h0; |
else if (clock[11:8] >= 4'h9) |
clock[15:12] <= clock[15:12] + 4'h1; |
end |
ck_pph <= (clock[15:0] == 16'h5959); |
|
if ((ck_pps)&&(ck_pph)) |
begin // advance the hours |
if (clock[21:16] >= 6'h23) |
begin |
clock[19:16] <= 4'h0; |
clock[21:20] <= 2'h0; |
end else if (clock[19:16] >= 4'h9) |
begin |
clock[19:16] <= 4'h0; |
clock[21:20] <= clock[21:20] + 2'h1; |
end else begin |
clock[19:16] <= clock[19:16] + 4'h1; |
end |
end |
ck_ppd <= (clock[21:0] == 22'h235959); |
|
|
if ((ck_sel)&&(i_wb_we)) |
begin |
if (8'hff != i_wb_data[7:0]) |
begin |
clock[7:0] <= i_wb_data[7:0]; |
ck_ppm <= (i_wb_data[7:0] == 8'h59); |
end |
if (8'hff != i_wb_data[15:8]) |
begin |
clock[15:8] <= i_wb_data[15:8]; |
ck_pph <= (i_wb_data[15:8] == 8'h59); |
end |
if (6'h3f != i_wb_data[21:16]) |
clock[21:16] <= i_wb_data[21:16]; |
clock[31:22] <= i_wb_data[31:22]; |
if (8'h00 == i_wb_data[7:0]) |
ck_sub <= 8'h00; |
end |
end |
|
// Clock updates take several clocks, so let's make sure we |
// are only looking at a valid clock value before testing it. |
reg [21:0] ck_last_clock; |
always @(posedge i_clk) |
ck_last_clock <= clock[21:0]; |
|
|
reg tm_pps, tm_ppm, tm_int; |
wire tm_stopped, tm_running, tm_alarm; |
assign tm_stopped = ~timer[24]; |
assign tm_running = timer[24]; |
assign tm_alarm = timer[25]; |
reg [23:0] tm_start; |
reg [7:0] tm_sub; |
initial tm_start = 24'h00; |
initial timer = 26'h00; |
initial tm_int = 1'b0; |
initial tm_pps = 1'b0; |
always @(posedge i_clk) |
begin |
if (ck_carry) |
begin |
tm_sub <= tm_sub + 8'h1; |
tm_pps <= (tm_sub == 8'hff); |
end else |
tm_pps <= 1'b0; |
|
if ((~tm_alarm)&&(tm_running)&&(tm_pps)) |
begin // If we are running ... |
timer[25] <= 1'b0; |
if (timer[23:0] == 24'h00) |
timer[25] <= 1'b1; |
else if (timer[3:0] != 4'h0) |
timer[3:0] <= timer[3:0]-4'h1; |
else begin // last digit is a zero |
timer[3:0] <= 4'h9; |
if (timer[7:4] != 4'h0) |
timer[7:4] <= timer[7:4]-4'h1; |
else begin // last two digits are zero |
timer[7:4] <= 4'h5; |
if (timer[11:8] != 4'h0) |
timer[11:8] <= timer[11:8]-4'h1; |
else begin // last three digits are zero |
timer[11:8] <= 4'h9; |
if (timer[15:12] != 4'h0) |
timer[15:12] <= timer[15:12]-4'h1; |
else begin |
timer[15:12] <= 4'h5; |
if (timer[19:16] != 4'h0) |
timer[19:16] <= timer[19:16]-4'h1; |
else begin |
// |
timer[19:16] <= 4'h9; |
timer[23:20] <= timer[23:20]-4'h1; |
end |
end |
end |
end |
end |
end |
|
if((~tm_alarm)&&(tm_running)) |
begin |
timer[25] <= (timer[23:0] == 24'h00); |
tm_int <= (timer[23:0] == 24'h00); |
end else tm_int <= 1'b0; |
if (tm_alarm) |
timer[24] <= 1'b0; |
|
if ((tm_sel)&&(i_wb_we)&&(tm_running)) // Writes while running |
// Only allowed to stop the timer, nothing more |
timer[24] <= i_wb_data[24]; |
else if ((tm_sel)&&(i_wb_we)&&(tm_stopped)) // Writes while off |
begin |
timer[24] <= i_wb_data[24]; |
if ((timer[24])||(i_wb_data[24])) |
timer[25] <= 1'b0; |
if (i_wb_data[23:0] != 24'h0000) |
begin |
timer[23:0] <= i_wb_data[23:0]; |
tm_start <= i_wb_data[23:0]; |
tm_sub <= 8'h00; |
end else if (timer[23:0] == 24'h00) |
begin // Resetting timer to last valid timer start val |
timer[23:0] <= tm_start; |
tm_sub <= 8'h00; |
end |
// Any write clears the alarm |
timer[25] <= 1'b0; |
end |
end |
|
// |
// Stopwatch functionality |
// |
// Setting bit '0' starts the stop watch, clearing it stops it. |
// Writing to the register with bit '1' high will clear the stopwatch, |
// and return it to zero provided that the stopwatch is stopped either |
// before or after the write. Hence, writing a '2' to the device |
// will always stop and clear it, whereas writing a '3' to the device |
// will only clear it if it was already stopped. |
reg sw_pps, sw_ppm, sw_pph; |
reg [7:0] sw_sub; |
wire sw_running; |
assign sw_running = stopwatch[0]; |
initial stopwatch = 32'h00000; |
always @(posedge i_clk) |
begin |
sw_pps <= 1'b0; |
if (sw_running) |
begin |
if (ck_carry) |
begin |
sw_sub <= sw_sub + 8'h1; |
sw_pps <= (sw_sub == 8'hff); |
end |
end |
|
stopwatch[7:1] <= sw_sub[7:1]; |
|
if (sw_pps) |
begin // Second hand |
if (stopwatch[11:8] >= 4'h9) |
stopwatch[11:8] <= 4'h0; |
else |
stopwatch[11:8] <= stopwatch[11:8] + 4'h1; |
|
if (stopwatch[15:8] >= 8'h59) |
stopwatch[15:12] <= 4'h0; |
else if (stopwatch[11:8] >= 4'h9) |
stopwatch[15:12] <= stopwatch[15:12] + 4'h1; |
sw_ppm <= (stopwatch[15:8] == 8'h59); |
end else sw_ppm <= 1'b0; |
|
if (sw_ppm) |
begin // Minutes |
if (stopwatch[19:16] >= 4'h9) |
stopwatch[19:16] <= 4'h0; |
else |
stopwatch[19:16] <= stopwatch[19:16]+4'h1; |
|
if (stopwatch[23:16] >= 8'h59) |
stopwatch[23:20] <= 4'h0; |
else if (stopwatch[19:16] >= 4'h9) |
stopwatch[23:20] <= stopwatch[23:20]+4'h1; |
sw_pph <= (stopwatch[23:16] == 8'h59); |
end else sw_pph <= 1'b0; |
|
if (sw_pph) |
begin // And hours |
if (stopwatch[27:24] >= 4'h9) |
stopwatch[27:24] <= 4'h0; |
else |
stopwatch[27:24] <= stopwatch[27:24]+4'h1; |
|
if((stopwatch[27:24] >= 4'h9)&&(stopwatch[31:28] < 4'hf)) |
stopwatch[31:28] <= stopwatch[27:24]+4'h1; |
end |
|
if ((sw_sel)&&(i_wb_we)) |
begin |
stopwatch[0] <= i_wb_data[0]; |
if((i_wb_data[1])&&((~stopwatch[0])||(~i_wb_data[0]))) |
begin |
stopwatch[31:1] <= 31'h00; |
sw_sub <= 8'h00; |
sw_pps <= 1'b0; |
sw_ppm <= 1'b0; |
sw_pph <= 1'b0; |
end |
end |
end |
|
// |
// The alarm code |
// |
// Set the alarm register to the time you wish the board to "alarm". |
// The "alarm" will take place once per day at that time. At that |
// time, the RTC code will generate a clock interrupt, and the CPU/host |
// can come and see that the alarm tripped. |
// |
// |
reg [21:0] alarm_time; |
reg al_int, // The alarm interrupt line |
al_enabled, // Whether the alarm is enabled |
al_tripped; // Whether the alarm has tripped |
initial al_enabled= 1'b0; |
initial al_tripped= 1'b0; |
always @(posedge i_clk) |
begin |
if ((al_sel)&&(i_wb_we)) |
begin |
// Only adjust the alarm hours if the requested hours |
// are valid. This allows writes to the register, |
// without a prior read, to leave these configuration |
// bits alone. |
if (i_wb_data[21:16] != 6'h3f) |
alarm_time[21:16] <= i_wb_data[21:16]; |
// Here's the same thing for the minutes: only adjust |
// the alarm minutes if the new bits are not all 1's. |
if (i_wb_data[15:8] != 8'hff) |
alarm_time[15:8] <= i_wb_data[15:8]; |
// Here's the same thing for the seconds: only adjust |
// the alarm minutes if the new bits are not all 1's. |
if (i_wb_data[7:0] != 8'hff) |
alarm_time[7:0] <= i_wb_data[7:0]; |
al_enabled <= i_wb_data[24]; |
// Reset the alarm if a '1' is written to the tripped |
// register, or if the alarm is disabled. |
if ((i_wb_data[25])||(~i_wb_data[24])) |
al_tripped <= 1'b0; |
end |
|
al_int <= 1'b0; |
if ((ck_last_clock != alarm_time)&&(clock[21:0] == alarm_time) |
&&(al_enabled)) |
begin |
al_tripped <= 1'b1; |
al_int <= 1'b1; |
end |
end |
|
// |
// The ckspeed register is equal to 2^48 divded by the number of |
// clock ticks you expect per second. Adjust high for a slower |
// clock, lower for a faster clock. In this fashion, a single |
// real time clock RTL file can handle tracking the clock in any |
// device. Further, because this is only the lower 32 bits of a |
// 48 bit counter per seconds, the clock jitter is kept below |
// 1 part in 65 thousand. |
// |
initial ckspeed = 32'd2814750; // 2af31e = 2^48 / 100e6 MHz |
// In the case of verilator, comment the above and uncomment the line |
// below. The clock constant below is "close" to simulation time, |
// meaning that my verilator simulation is running about 300x slower |
// than board time. |
// initial ckspeed = 32'd786432000; |
always @(posedge i_clk) |
if ((sp_sel)&&(i_wb_we)) |
ckspeed <= i_wb_data; |
|
assign o_interrupt = tm_int || al_int; |
|
// A once-per day strobe, on the last second of the day so that the |
// the next clock is the first clock of the day. This is useful for |
// connecting this module to a year/month/date date/calendar module. |
assign o_ppd = (ck_ppd)&&(ck_pps); |
|
always @(posedge i_clk) |
case(i_wb_addr[2:0]) |
3'b000: o_data <= { clock[31:22], ck_last_clock }; |
3'b001: o_data <= { 6'h00, timer }; |
3'b010: o_data <= stopwatch; |
3'b011: o_data <= { 6'h00, al_tripped, al_enabled, 2'b00, alarm_time }; |
3'b100: o_data <= ckspeed; |
default: o_data <= 32'h000; |
endcase |
|
endmodule |
/trunk/rtl/rtcclock.v
45,7 → 45,7
o_data, // multiplexed based upon i_wb_addr |
// Output controls |
o_sseg, o_led, o_interrupt, |
// |
// A once-per-day strobe on the last clock of the day |
o_ppd, |
// Time setting hack(s) |
i_hack); |
423,29 → 423,29
end |
|
reg [15:0] h_sseg; |
reg [3:0] dmask; |
reg [3:1] dmask; |
always @(posedge i_clk) |
case(clock[27:24]) |
4'h1: begin h_sseg <= timer[15:0]; |
if (tm_alarm) dmask <= 4'hf; |
if (tm_alarm) dmask <= 3'h7; |
else begin |
dmask[3] <= (12'h000 != timer[23:12]); // timer[15:12] |
dmask[2] <= (16'h000 != timer[23: 8]); // timer[11: 8] |
dmask[1] <= (20'h000 != timer[23: 4]); // timer[ 7: 4] |
dmask[0] <= 1'b1; // Always on |
// dmask[0] <= 1'b1; // Always on |
end end |
4'h2: begin h_sseg <= stopwatch[19:4]; |
dmask[3] <= (12'h00 != stopwatch[27:16]); |
dmask[2] <= (16'h000 != stopwatch[27:12]); |
dmask[1] <= 1'b1; // Always on, stopwatch[11:8] |
dmask[0] <= 1'b1; // Always on, stopwatch[7:4] |
// dmask[0] <= 1'b1; // Always on, stopwatch[7:4] |
end |
4'h3: begin h_sseg <= ck_last_clock[15:0]; |
dmask[3:0] <= 4'hf; |
dmask[3:1] <= 3'h7; |
end |
default: begin // 4'h0 |
h_sseg <= { 2'b00, ck_last_clock[21:8] }; |
dmask[2:0] <= 3'hf; |
dmask[2:1] <= 2'b11; |
dmask[3] <= (2'b00 != ck_last_clock[21:20]); |
end |
endcase |
468,7 → 468,7
(dmask[3])?w_sseg[31:24]:8'h00, |
(dmask[2])?w_sseg[23:16]:8'h00, |
(dmask[1])?w_sseg[15: 8]:8'h00, |
(dmask[0])?w_sseg[ 7: 0]:8'h00 }; |
w_sseg[ 7: 0] }; |
|
reg [17:0] ledreg; |
always @(posedge i_clk) |