pygar: core/src/BFIFO.bsv annotate

annotate core/src/BFIFO.bsv @ 23:90197e3375e2 pygar svn.24

[svn r24] added testing, but something is wrong with our c++ file.

author	rlm
date	Wed, 28 Apr 2010 08:19:09 -0400
parents	91a1f76ddd62
children

rev	line source
punk@1	1 import FIFO::*;
punk@1	2 import FIFOF::*;
punk@1	3 import List::*;
punk@1	4 import Assert::*;
punk@1	5
punk@1	6 module mkBFIFO1( FIFO#(item_t) ) provisos ( Bits#(item_t,item_sz) );
punk@1	7
punk@1	8 RWire#(item_t) inputWire <- mkRWire();
punk@1	9 PulseWire deqEnabled <- mkPulseWire();
punk@1	10 PulseWire clearEnabled <- mkPulseWire();
punk@1	11
punk@1	12 Reg#(item_t) register <- mkRegU();
punk@1	13 Reg#(Bool) valid <- mkReg(False);
punk@1	14
punk@1	15 // If there is an input item on the inputWire wire and dequeue did not
punk@1	16 // execute this cycle then we need to store the item in the register
punk@1	17
punk@1	18 (fire_when_enabled)
punk@1	19 rule update ( True );
punk@1	20 case (inputWire.wget()) matches
punk@1	21 tagged Invalid:
punk@1	22 if (deqEnabled \|\| clearEnabled)
punk@1	23 valid <= False;
punk@1	24 tagged Valid .x:
punk@1	25 begin
punk@1	26 register <= x;
punk@1	27 valid <= !(deqEnabled \|\| clearEnabled);
punk@1	28 end
punk@1	29 endcase
punk@1	30 endrule
punk@1	31
punk@1	32 // On enqueue we write the input item to the inputWire wire
punk@1	33
punk@1	34 method Action enq( item_t item ) if ( !valid );
punk@1	35 inputWire.wset(item);
punk@1	36 endmethod
punk@1	37
punk@1	38 // On dequeue we always invalidate the storage register regardless
punk@1	39 // of whether or not the item was actually bypassed or not. We also
punk@1	40 // set a combinational signal so that we know not to move the item
punk@1	41 // into the register this cycle.
punk@1	42
punk@1	43 method Action deq() if ( valid \|\| isValid(inputWire.wget()) );
punk@1	44 deqEnabled.send();
punk@1	45 endmethod
punk@1	46
punk@1	47 // We get the item either from the register (if register is valid) or
punk@1	48 // from the combinational bypasss (if the rwire is valid).
punk@1	49
punk@1	50 method item_t first() if ( valid \|\| isValid(inputWire.wget()) );
punk@1	51 if ( valid )
punk@1	52 return register;
punk@1	53 else
punk@1	54 return unJust(inputWire.wget());
punk@1	55 endmethod
punk@1	56
punk@1	57 method Action clear();
punk@1	58 clearEnabled.send();
punk@1	59 endmethod
punk@1	60
punk@1	61 endmodule
punk@1	62
punk@1	63 module mkSizedBFIFO#(Integer n) ( FIFO#(item_t) ) provisos ( Bits#(item_t,item_sz) );
punk@1	64
punk@1	65 RWire#(item_t) inputWire <- mkRWire();
punk@1	66 PulseWire deqEnabled <- mkPulseWire();
punk@1	67 PulseWire clearEnabled <- mkPulseWire();
punk@1	68
punk@1	69 List#(Reg#(item_t)) registers <- replicateM(n, mkRegU);
punk@1	70 List#(Reg#(Bool)) valids <- replicateM(n, mkReg(False));
punk@1	71
punk@1	72 function Nat getNextFree (List#(Reg#(Bool)) vs);
punk@1	73
punk@1	74 Nat res = fromInteger(n - 1);
punk@1	75
punk@1	76 for (Integer x = n - 1; x > -1; x = x - 1)
punk@1	77 res = !vs[x]._read() ? fromInteger(x) : res;
punk@1	78
punk@1	79 return res;
punk@1	80
punk@1	81 endfunction
punk@1	82
punk@1	83 function Bool notFull();
punk@1	84
punk@1	85 Bool full = True;
punk@1	86
punk@1	87 for (Integer x = 0; x < length(valids); x = x + 1)
punk@1	88 full = full && valids[x]._read();
punk@1	89
punk@1	90 return !full;
punk@1	91
punk@1	92 endfunction
punk@1	93 // If there is an input item on the inputWire wire and dequeue did not
punk@1	94 // execute this cycle then we need to store the item in the register
punk@1	95
punk@1	96 rule update ( True );
punk@1	97 Nat next = getNextFree(valids);
punk@1	98
punk@1	99 next = (deqEnabled) ? next - 1 : next;
punk@1	100
punk@1	101 (valids[next]) <= isValid(inputWire.wget());
punk@1	102 (registers[next]) <= validValue(inputWire.wget());
punk@1	103
punk@1	104 if (deqEnabled && !clearEnabled)
punk@1	105 begin
punk@1	106
punk@1	107 for (Nat x = 0; x < (next - 1); x = x + 1)
punk@1	108 begin
punk@1	109 (valids[x]) <= valids[x+1]._read();
punk@1	110 (registers[x]) <= registers[x+1]._read();
punk@1	111 end
punk@1	112
punk@1	113 end
punk@1	114 else if (clearEnabled)
punk@1	115 begin
punk@1	116
punk@1	117 for (Integer x = 0; x < n; x = x + 1)
punk@1	118 (valids[x]) <= False;
punk@1	119
punk@1	120 end
punk@1	121 endrule
punk@1	122
punk@1	123 // On enqueue we write the input item to the inputWire wire
punk@1	124
punk@1	125 method Action enq( item_t item ) if ( notFull );
punk@1	126 inputWire.wset(item);
punk@1	127 endmethod
punk@1	128
punk@1	129 // On dequeue we always invalidate the storage register regardless
punk@1	130 // of whether or not the item was actually bypassed or not. We also
punk@1	131 // set a combinational signal so that we know not to move the item
punk@1	132 // into the register this cycle.
punk@1	133
punk@1	134 method Action deq() if ( valids[0]._read() \|\| isValid(inputWire.wget()) );
punk@1	135 deqEnabled.send();
punk@1	136 endmethod
punk@1	137
punk@1	138 // We get the item either from the register (if register is valid) or
punk@1	139 // from the combinational bypasss (if the rwire is valid).
punk@1	140
punk@1	141 method item_t first() if ( valids[0]._read() \|\| isValid(inputWire.wget()) );
punk@1	142 if ( valids[0]._read() )
punk@1	143 return registers[0]._read();
punk@1	144 else
punk@1	145 return unJust(inputWire.wget());
punk@1	146 endmethod
punk@1	147
punk@1	148
punk@1	149 method Action clear();
punk@1	150 clearEnabled.send();
punk@1	151 endmethod
punk@1	152
punk@1	153 endmodule
punk@1	154
punk@1	155
punk@1	156 module mkBFIFOF1( FIFOF#(item_t) ) provisos ( Bits#(item_t,item_sz) );
punk@1	157
punk@1	158 RWire#(item_t) inputWire <- mkRWire();
punk@1	159 RWire#(Bool) deqEnabled <- mkRWire();
punk@1	160
punk@1	161 Reg#(Maybe#(item_t)) register <- mkReg(Invalid);
punk@1	162
punk@1	163 // If there is an input item on the inputWire wire and dequeue did not
punk@1	164 // execute this cycle then we need to store the item in the register
punk@1	165
punk@1	166 rule noDeq ( isValid(inputWire.wget()) && !isValid(deqEnabled.wget()) );
punk@1	167 register <= inputWire.wget();
punk@1	168 endrule
punk@1	169
punk@1	170 // On enqueue we write the input item to the inputWire wire
punk@1	171
punk@1	172 method Action enq( item_t item ) if ( !isValid(register) );
punk@1	173 inputWire.wset(item);
punk@1	174 endmethod
punk@1	175
punk@1	176 // On dequeue we always invalidate the storage register regardless
punk@1	177 // of whether or not the item was actually bypassed or not. We also
punk@1	178 // set a combinational signal so that we know not to move the item
punk@1	179 // into the register this cycle.
punk@1	180
punk@1	181 method Action deq() if ( isValid(register) \|\| isValid(inputWire.wget()) );
punk@1	182 register <= Invalid;
punk@1	183 deqEnabled.wset(True);
punk@1	184 endmethod
punk@1	185
punk@1	186 // We get the item either from the register (if register is valid) or
punk@1	187 // from the combinational bypasss (if the rwire is valid).
punk@1	188
punk@1	189 method item_t first() if ( isValid(register) \|\| isValid(inputWire.wget()) );
punk@1	190 if ( isValid(register) )
punk@1	191 return unJust(register);
punk@1	192 else
punk@1	193 return unJust(inputWire.wget());
punk@1	194 endmethod
punk@1	195
punk@1	196 // FIFOF adds the following two methods
punk@1	197
punk@1	198 method Bool notFull();
punk@1	199 return !isValid(register);
punk@1	200 endmethod
punk@1	201
punk@1	202 method Bool notEmpty();
punk@1	203 return (isValid(register) \|\| isValid(inputWire.wget()));
punk@1	204 endmethod
punk@1	205
punk@1	206 // Not sure about the clear method ...
punk@1	207
punk@1	208 method Action clear();
punk@1	209 dynamicAssert( False, "BFIFO.clear() not implemented yet!" );
punk@1	210 endmethod
punk@1	211
punk@1	212 endmodule
punk@1	213
punk@1	214 (* synthesize *)
punk@1	215 module mkBFIFO_16 (FIFO#(Bit#(16)));
punk@1	216
punk@1	217 let f <- mkBFIFO1();
punk@1	218
punk@1	219 return f;
punk@1	220
punk@1	221 endmodule
punk@1	222

Mercurial > pygar

annotate core/src/BFIFO.bsv @ 23:90197e3375e2 pygar svn.24