diff --git a/cpld/CNT.v b/cpld/CNT.v index 96f8d8b..c8ab7e9 100644 --- a/cpld/CNT.v +++ b/cpld/CNT.v @@ -2,7 +2,7 @@ module CNT( /* FSB clock and E clock inputs */ input CLK, input C8M, input E, /* Refresh request */ - output reg RefReq, output reg RefUrg, + output reg RefReq, output RefUrg, /* Reset, button */ output reg nRESout, input nRESin, input nIPL2, /* Mac PDS bus master control outputs */ @@ -22,10 +22,6 @@ module CNT( /* C8M clock synchronization */ reg [3:0] C8Mr; always @(posedge CLK) C8Mr[3:0] <= { C8Mr[2:0], C8M }; - /* NMI and reset synchronization */ - reg nIPL2r; always @(posedge CLK) nIPL2r <= nIPL2; - reg nRESr; always @(posedge CLK) nRESr <= nRESin; - /* Timer counts from 0 to 1010 (10) -- 11 states == 14.042 us * Refresh timer sequence * | Timer | RefReq | RefUrg | @@ -38,46 +34,50 @@ module CNT( * | 5 0101 | 1 | 0 | * | 6 0110 | 1 | 0 | * | 7 0111 | 1 | 0 | - * | 8 1000 | 1 | 0 | + * | 8 1000 | 1 | 1 | * | 9 1001 | 1 | 1 | * | 10 1010 | 1 | 1 | * back to timer==0 */ reg [3:0] Timer = 0; wire TimerTC = Timer==10; + assign RefUrg = Timer[3]; reg TimerTick; always @(posedge CLK) begin if (EFall) begin if (TimerTC) Timer <= 0; else Timer <= Timer+1; - RefUrg <= Timer==8 || Timer==9; RefReq <= Timer!=10; end end always @(posedge CLK) TimerTick <= EFall && TimerTC; - /* QoS select latch */ - reg QoSCSr; - always @(posedge CLK) QoSCSr <= (BACT && (QoSCS || SndQoSCS)) || !nRESr; + /* QoS select latches */ + reg QoSCSr, SndQoSCSr; + always @(posedge CLK) QoSCSr <= (BACT && QoSCS) || !nRESin; + always @(posedge CLK) SndQoSCSr <= BACT && SndQoSCS; + + /* Wait state timer */ + reg [3:0] Wait; + always @(posedge CLK) begin + if (!BACT) Wait <= 0; + else Wait <= Wait+1; + end /* QoS timer * In the absence of a QoS trigger, QS==0. * When Qos triggered, QS is set to 1 and counts 1, 2, 3, 0. * While QS!=0, QoS is enabled. - * QoS enable period is 28.124 us - 42.240 us */ + * QoS enable period is 196.588 us - 210.630 us */ reg [3:0] QS; always @(posedge CLK) begin - if (QoSCSr) QS <= 15; + if (SndQoSCSr || QoSCSr) QS <= 15; else if (QS==0) QS <= 0; else if (TimerTick) QS <= QS-1; end /* QoS enable control */ always @(posedge CLK) if (!BACT) QoSEN <= QS!=0; - - /* Sound QoS select latch */ - reg SndQoSCSr; - always @(posedge CLK) SndQoSCSr <= BACT && SndQoSCS; /* Sound QoS timer */ reg [1:0] SndQS; @@ -88,17 +88,10 @@ module CNT( else if (TimerTick) SndQS <= SndQS-1; end - /* Wait state timer */ - reg [3:0] Wait; - always @(posedge CLK) begin - if (!BACT) Wait <= 0; - else Wait <= Wait+1; - end - /* Sound QoS ready control */ always @(posedge CLK) begin if (!BACT) SndQoSReady <= SndQS==0; - else if (QoSCSr && !SndQoSCSr) SndQoSReady <= 1; + else if (QoSCSr) SndQoSReady <= 1; else if (Wait==15) SndQoSReady <= 1; end @@ -124,7 +117,7 @@ module CNT( else case (IS[1:0]) 0: if (LTimerTick) IS <= 1; 1: if (LTimerTick) IS <= 2; - 2: if (LTimerTick && nIPL2r) IS <= 3; + 2: if (LTimerTick && nIPL2) IS[0] <= 1; 3: IS <= 3; endcase end @@ -139,7 +132,7 @@ module CNT( end 2: begin AoutOE <= 0; nRESout <= 0; - if (!nIPL2r) nBR_IOB <= 1; // Disable bus request if NMI pressed + if (!nIPL2) nBR_IOB <= 1; // Disable bus request if NMI pressed end 3: begin AoutOE <= !nBR_IOB; if (LTimerTick) nRESout <= 1; // Release reset after a while diff --git a/cpld/CS.v b/cpld/CS.v index b6707d4..863365e 100644 --- a/cpld/CS.v +++ b/cpld/CS.v @@ -49,7 +49,7 @@ module CS( wire SndRAMCSWR = VidRAMCSWR64k && ( ((A[15:12]==4'hF) && (A[11:8]==4'hD || A[11:8]==4'hE || A[11:8]==4'hF)) || ((A[15:12]==4'hA) && (A[11:8]==4'h1 || A[11:8]==4'h2 || A[11:8]==4'h3))); - assign QoSCS = IACKCS || VIACS || IWMCS || SCCCS || SCSICS || SndRAMCSWR; + assign QoSCS = IACKCS || VIACS || IWMCS || SCCCS || SCSICS; assign SndQoSCS = SndRAMCSWR; /* Select signals - IOB domain */