summaryrefslogtreecommitdiff
path: root/rtl/vhdl/T51_TC01.vhd
blob: 5740192ba7f9aac0d089649a25893e7a427fd262 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
--
-- 8051 compatible microcontroller core
--
-- Version : 0300
--
-- Copyright (c) 2001-2002 Daniel Wallner (jesus@opencores.org)
--           (c) 2004-2005 Andreas Voggeneder (andreas.voggeneder@fh-hagenberg.at)
--
-- All rights reserved
--
-- Redistribution and use in source and synthezised forms, with or without
-- modification, are permitted provided that the following conditions are met:
--
-- Redistributions of source code must retain the above copyright notice,
-- this list of conditions and the following disclaimer.
--
-- Redistributions in synthesized form must reproduce the above copyright
-- notice, this list of conditions and the following disclaimer in the
-- documentation and/or other materials provided with the distribution.
--
-- Neither the name of the author nor the names of other contributors may
-- be used to endorse or promote products derived from this software without
-- specific prior written permission.
--
-- THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
-- AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
-- THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
-- PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE
-- LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
-- CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
-- SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
-- INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
-- CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
-- ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
-- POSSIBILITY OF SUCH DAMAGE.
--
-- Please report bugs to the author, but before you do so, please
-- make sure that this is not a derivative work and that
-- you have the latest version of this file.
--
-- The latest version of this file can be found at:
--	http://www.opencores.org/cvsweb.shtml/t51/
--
-- Limitations :
--
-- File history :
--

library IEEE;
use IEEE.std_logic_1164.all;
use IEEE.numeric_std.all;

entity T51_TC01 is
	generic(
		FastCount	: integer := 0;
		tristate  : integer := 1
	);
	port(
		Clk			: in std_logic;
		Rst_n		: in std_logic;
		T0			: in std_logic;
		T1			: in std_logic;
		INT0		: in std_logic;
		INT1		: in std_logic;
		M_Sel		: in std_logic;
		H0_Sel		: in std_logic;
		L0_Sel		: in std_logic;
		H1_Sel		: in std_logic;
		L1_Sel		: in std_logic;
		R0			: in std_logic;
		R1			: in std_logic;
		M_Wr		: in std_logic;
		H0_Wr		: in std_logic;
		L0_Wr		: in std_logic;
		H1_Wr		: in std_logic;
		L1_Wr		: in std_logic;
		Data_In		: in std_logic_vector(7 downto 0);
		Data_Out	: out std_logic_vector(7 downto 0);
		OF0			: out std_logic;
		OF1			: out std_logic
	);
end T51_TC01;

architecture rtl of T51_TC01 is

	signal	TMOD		: std_logic_vector(7 downto 0);
	signal	Cnt0		: std_logic_vector(15 downto 0);
	signal	Cnt1		: std_logic_vector(15 downto 0);

	signal	Tick0		: std_logic;
	signal	Tick1		: std_logic;
	signal	Tick12		: std_logic;

begin

	-- Registers and counter
	tristate_mux: if tristate/=0 generate
  	Data_Out <= Cnt0(15 downto 8) when H0_Sel = '1' else "ZZZZZZZZ";
  	Data_Out <= Cnt0(7 downto 0) when L0_Sel = '1' else "ZZZZZZZZ";
  	Data_Out <= Cnt1(15 downto 8) when H1_Sel = '1' else "ZZZZZZZZ";
  	Data_Out <= Cnt1(7 downto 0) when L1_Sel = '1' else "ZZZZZZZZ";
  	Data_Out <= TMOD when M_Sel = '1' else "ZZZZZZZZ";
  end generate;
	
	std_mux: if tristate=0 generate
  	Data_Out <= Cnt0(15 downto 8) when H0_Sel = '1' else
  	            Cnt0(7 downto 0) when L0_Sel = '1' else
  	            Cnt1(15 downto 8) when H1_Sel = '1' else
  	            Cnt1(7 downto 0) when L1_Sel = '1' else
  	            TMOD when M_Sel = '1' else 
  	            (others =>'-');
	end generate;
	
	process (Rst_n, Clk)
	begin
		if Rst_n = '0' then
			TMOD <= (others => '0');
			Cnt0 <= (others => '0');
			Cnt1 <= (others => '0');
			OF0 <= '0';
			OF1 <= '0';
		elsif Clk'event and Clk = '1' then
			OF0 <= '0';
			OF1 <= '0';
			if TMOD(1 downto 0) = "00" then
				if Tick0 = '1' then
					Cnt0(12 downto 0) <= std_logic_vector(unsigned(Cnt0(12 downto 0)) + 1);
					if Cnt0(12 downto 0) = "1111111111111" then
						OF0 <= '1';
					end if;
				end if;
			end if;
			if TMOD(5 downto 4) = "00" then
				if Tick1 = '1' then
					Cnt1(12 downto 0) <= std_logic_vector(unsigned(Cnt1(12 downto 0)) + 1);
					if Cnt1(12 downto 0) = "1111111111111" then
						OF1 <= '1';
					end if;
				end if;
			end if;
			if TMOD(1 downto 0) = "01" then
				if Tick0 = '1' then
					Cnt0 <= std_logic_vector(unsigned(Cnt0) + 1);
					if Cnt0 = "1111111111111111" then
						OF0 <= '1';
					end if;
				end if;
			end if;
			if TMOD(5 downto 4) = "01" then
				if Tick1 = '1' then
					Cnt1 <= std_logic_vector(unsigned(Cnt1) + 1);
					if Cnt1 = "1111111111111111" then
						OF1 <= '1';
					end if;
				end if;
			end if;
			if TMOD(1 downto 0) = "10" then
				if Tick0 = '1' then
					Cnt0(7 downto 0) <= std_logic_vector(unsigned(Cnt0(7 downto 0)) + 1);
					if Cnt0(7 downto 0) = "11111111" then
						Cnt0(7 downto 0) <= Cnt0(15 downto 8);
						OF0 <= '1';
					end if;
				end if;
			end if;
			if TMOD(5 downto 4) = "10" then
				if Tick1 = '1' then
					Cnt1(7 downto 0) <= std_logic_vector(unsigned(Cnt1(7 downto 0)) + 1);
					if Cnt1(7 downto 0) = "11111111" then
						Cnt1(7 downto 0) <= Cnt1(15 downto 8);
						OF1 <= '1';
					end if;
				end if;
			end if;
			if TMOD(1 downto 0) = "11" then
				if Tick0 = '1' then
					Cnt0(7 downto 0) <= std_logic_vector(unsigned(Cnt0(7 downto 0)) + 1);
					if Cnt0(7 downto 0) = "11111111" then
						OF0 <= '1';
					end if;
				end if;
				OF1 <= '0';
				if R1 = '1' and Tick12 = '1' then
					Cnt0(15 downto 8) <= std_logic_vector(unsigned(Cnt0(15 downto 8)) + 1);
					if Cnt1(15 downto 8) = "11111111" then
						OF1 <= '1';
					end if;
				end if;
			end if;

			-- Register write
			if M_Wr = '1' then
				TMOD <= Data_In;
			end if;
			if H0_Wr = '1' then
				Cnt0(15 downto 8) <= Data_In;
			end if;
			if L0_Wr = '1' then
				Cnt0(7 downto 0) <= Data_In;
			end if;
			if H1_Wr = '1' then
				Cnt1(15 downto 8) <= Data_In;
			end if;
			if L1_Wr = '1' then
				Cnt1(7 downto 0) <= Data_In;
			end if;
		end if;
	end process;

	-- Tick generator
	process (Clk, Rst_n)
		variable Prescaler : unsigned(3 downto 0);
		variable T0_r : std_logic_vector(1 downto 0);
		variable T1_r : std_logic_vector(1 downto 0);
		variable I0_r : std_logic_vector(1 downto 0);
		variable I1_r : std_logic_vector(1 downto 0);
	begin
		if Rst_n = '0' then
			Prescaler := (others => '0');
			Tick0 <= '0';
			Tick1 <= '0';
			Tick12 <= '0';
			T0_r := "00";
			T1_r := "00";
			I0_r := "00";
			I1_r := "00";
		elsif Clk'event and Clk='1' then
			Tick0 <= '0';
			Tick1 <= '0';
			Tick12 <= '0';

			if R0 = '1' and (I0_r(1) = '1' or TMOD(3) = '0') then
				if TMOD(2) = '1' then
					Tick0 <= T0_r(0) and not T0_r(1);
				else
					Tick0 <= Tick12;
				end if;
			end if;

			if R1 = '1' and (I1_r(1) = '1' or TMOD(7) = '0') then
				if TMOD(6) = '1' then
					Tick1 <= T1_r(0) and not T1_r(1);
				else
					Tick1 <= Tick12;
				end if;
			end if;

			T0_r(1) := T0_r(0);
			T1_r(1) := T1_r(0);
			T0_r(0) := T0;
			T1_r(0) := T1;

			I0_r(1) := I0_r(0);
			I1_r(1) := I1_r(0);
			I0_r(0) := INT0;
			I1_r(0) := INT1;

			if Prescaler = "1011" then
				Prescaler := "0000";
				Tick12 <= '1';
			else
				Prescaler := Prescaler + 1;
			end if;
			if FastCount/=0 then
				Tick12 <= '1';
			end if;
		end if;
	end process;

end;