FSM trouble

here is the working FSM. I like this better as it is easier to see the output states along with the state priority in one shot.

reg [7:0] Rps2_command;

reg Rps2_send_command;

assign ps2_send_command = Rps2_send_command;

assign ps2_command = Rps2_command;

/*****************************************************************************

* Finite State Machine(s) *

*****************************************************************************/

// This FSM resets the PS/2 device and then keeps track of packets, which

// consist of three data bytes. Packets could be from a key board or mouse,

// but this code is needed only for tracking movements of the mouse.

always @(y_Q, was_sent, ps2_data_en, plugged_in, ack_received)

begin: state_table

case (y_Q)

S0:

begin

Rps2_send_command <= 1'b1;//S0 output values

Rps2_command <= 8'hF4;

mouse_packet <= 1'b0;

if

(was_sent==1'b1)//state priority 1

Y_D<=S1;

else

Y_D<=S0;//state priority 2

end

S1:

begin

Rps2_send_command <= 1'b0;//S1 output values

Rps2_command <= 8'hF4;

mouse_packet <= 1'b0;

if

(ack_received==1'b1)//state priority 1

Y_D= S2;

else

Y_D= S1;//state priority 2

end

S2:

begin

Rps2_send_command <= 1'b1;//S2 output values

Rps2_command <= 8'hF4;

mouse_packet <= 1'b0;

if

(ps2_data_en==1'b1)//state priority 1

Y_D= S3;

else

Y_D= S2;//state priority 2

end

S3:

begin

Rps2_send_command <= 1'b1;//S3 output values

Rps2_command <= 8'hF4;

mouse_packet <= 1'b0;

if

(plugged_in==1'b1)//state priority 1

Y_D= S0;

else if

(ps2_data_en==1'b0)//state priority 2

Y_D= S3;

else

Y_D= S4;//state priority 3 when plugged_in==0 and ps2_data_en==1

end

S4:

begin

Rps2_send_command <= 1'b1;//S4 output values

Rps2_command <= 8'hF4;

mouse_packet <= 1'b0;

if

(plugged_in==1'b1)//state priority 1

Y_D= S0;

else if

(ps2_data_en==1'b0)//state priority 2

Y_D= S4;

else

Y_D= S5;//state priority 3 when plugged_in==0 and ps2_data_en==1

end

S5:

begin

if

(!plugged_in)

mouse_packet=1'b1;//S5 output values

if (plugged_in==1'b1)//state priority 1

Y_D= S0;

else

Y_D= S4;//state priority 2

end

default: Y_D = 3'bxxx;

endcase

end // state_table