X-Git-Url: http://git.joshuawise.com/firearm.git/blobdiff_plain/ab7ee9fcbd14c1f6ce57e5efcebbaf231a50c48c..d0e6b3ca86dc90cd78057c0df333d880985d6684:/Memory.v?ds=inline diff --git a/Memory.v b/Memory.v index eb0f69f..eb4006f 100644 --- a/Memory.v +++ b/Memory.v @@ -13,6 +13,7 @@ module Memory( input rw_wait, output reg [31:0] wr_data, input [31:0] rd_data, + output reg [2:0] data_size, /* regfile interface */ output reg [3:0] st_read, @@ -52,9 +53,9 @@ module Memory( ); reg [31:0] addr, raddr, prev_raddr, next_regdata, next_outcpsr; + reg [31:0] prevaddr; reg [3:0] next_regsel, cur_reg, prev_reg; reg next_writeback; - reg [31:0] align_s1, align_s2, align_rddata; wire next_outbubble; wire next_write_reg; @@ -62,6 +63,12 @@ module Memory( wire [31:0] next_write_data; reg [1:0] lsr_state = 2'b01, next_lsr_state; + reg [31:0] align_s1, align_s2, align_rddata; + + reg [1:0] lsrh_state = 2'b01, next_lsrh_state; + reg [31:0] lsrh_rddata; + reg [15:0] lsrh_rddata_s1; + reg [7:0] lsrh_rddata_s2; reg [15:0] regs, next_regs; reg [2:0] lsm_state = 3'b001, next_lsm_state; @@ -85,36 +92,43 @@ module Memory( outcpsr <= next_outcpsr; outspsr <= spsr; swp_state <= next_swp_state; + lsm_state <= next_lsm_state; + lsr_state <= next_lsr_state; + lsrh_state <= next_lsrh_state; + prevaddr <= addr; end always @(*) begin - addr = 32'hxxxxxxxx; + addr = prevaddr; raddr = 32'hxxxxxxxx; rd_req = 1'b0; wr_req = 1'b0; wr_data = 32'hxxxxxxxx; busaddr = 32'hxxxxxxxx; + data_size = 3'bxxx; outstall = 1'b0; next_write_reg = write_reg; next_write_num = write_num; next_write_data = write_data; next_outbubble = inbubble; - outstall = 1'b0; next_regs = regs; cp_req = 1'b0; cp_rnw = 1'bx; cp_write = 32'hxxxxxxxx; offset = prev_offset; next_outcpsr = lsm_state == 3'b010 ? outcpsr : cpsr; + lsrh_rddata = 32'hxxxxxxxx; + lsrh_rddata_s1 = 16'hxxxx; + lsrh_rddata_s2 = 8'hxx; next_lsm_state = lsm_state; next_lsr_state = lsr_state; + next_lsrh_state = lsrh_state; next_swp_oldval = swp_oldval; next_swp_state = swp_state; cur_reg = prev_reg; /* XXX shit not given about endianness */ - /* TODO ldrh/strh */ if (flush) next_outbubble = 1'b1; else casez(insn) @@ -122,6 +136,7 @@ module Memory( outstall = rw_wait; next_outbubble = rw_wait; busaddr = {op0[31:2], 2'b0}; + data_size = insn[22] ? 3'b001 : 3'b100; case(swp_state) 2'b01: begin rd_req = 1'b1; @@ -133,41 +148,93 @@ module Memory( end 2'b10: begin wr_req = 1'b1; - wr_data = op1; + wr_data = insn[22] ? {4{op1[7:0]}} : op1; next_write_reg = 1'b1; next_write_num = insn[15:12]; - next_write_data = swp_oldval; + next_write_data = insn[22] ? {24'b0, swp_oldval[7:0]} : swp_oldval; if(!rw_wait) next_swp_state = 2'b01; end default: begin end endcase end + `DECODE_ALU_HDATA_REG, + `DECODE_ALU_HDATA_IMM: if(!inbubble) begin + next_outbubble = rw_wait; + outstall = rw_wait; + addr = insn[23] ? op0 + op1 : op0 - op1; /* up/down select */ + raddr = insn[24] ? op0 : addr; /* pre/post increment */ + busaddr = raddr; + /* rotate to correct position */ + case(insn[6:5]) + 2'b00: begin end /* swp */ + 2'b01: begin /* unsigned half */ + wr_data = {2{op2[15:0]}}; /* XXX need to store halfword */ + data_size = 3'b010; + lsrh_rddata = {16'b0, raddr[1] ? rd_data[31:16] : rd_data[15:0]}; + end + 2'b10: begin /* signed byte */ + wr_data = {4{op2[7:0]}}; + data_size = 3'b001; + lsrh_rddata_s1 = raddr[1] ? rd_data[31:16] : rd_data[15:0]; + lsrh_rddata_s2 = raddr[0] ? lsrh_rddata_s1[15:8] : lsrh_rddata_s1[7:0]; + lsrh_rddata = {{24{lsrh_rddata_s2[7]}}, lsrh_rddata_s2}; + end + 2'b11: begin /* signed half */ + wr_data = {2{op2[15:0]}}; + data_size = 3'b010; + lsrh_rddata = raddr[1] ? {{16{rd_data[31]}}, rd_data[31:16]} : {{16{rd_data[15]}}, rd_data[15:0]}; + end + endcase + + case(lsrh_state) + 2'b01: begin + rd_req = insn[20]; + wr_req = ~insn[20]; + next_write_num = insn[15:12]; + next_write_data = lsrh_rddata; + if(insn[20]) begin + next_write_reg = 1'b1; + end + if(insn[21] | !insn[24]) begin + outstall = 1'b1; + if(!rw_wait) + next_lsrh_state = 2'b10; + end + end + 2'b10: begin + next_write_reg = 1'b1; + next_write_num = insn[19:16]; + next_write_data = addr; + next_lsrh_state = 2'b10; + end + default: begin end + endcase + end `DECODE_LDRSTR_UNDEFINED: begin end `DECODE_LDRSTR: if(!inbubble) begin next_outbubble = rw_wait; outstall = rw_wait; addr = insn[23] ? op0 + op1 : op0 - op1; /* up/down select */ raddr = insn[24] ? op0 : addr; /* pre/post increment */ - busaddr = {raddr[31:2], 2'b0}; - /* rotate to correct position */ + busaddr = raddr; + /* rotate to correct position */ align_s1 = raddr[1] ? {rd_data[15:0], rd_data[31:16]} : rd_data; align_s2 = raddr[0] ? {align_s1[7:0], align_s1[31:8]} : align_s1; /* select byte or word */ align_rddata = insn[22] ? {24'b0, align_s2[7:0]} : align_s2; - if(!insn[20]) begin - wr_data = insn[22] ? {4{op2[7:0]}} : op2; /* XXX need to actually store just a byte */ - end + wr_data = insn[22] ? {4{op2[7:0]}} : op2; /* XXX need to actually store just a byte */ + data_size = insn[22] ? 3'b001 : 3'b100; case(lsr_state) 2'b01: begin rd_req = insn[20]; wr_req = ~insn[20]; + next_write_reg = 1'b1; + next_write_num = insn[15:12]; if(insn[20]) begin - next_write_reg = 1'b1; - next_write_num = insn[15:12]; next_write_data = align_rddata; end - if(insn[21]) begin + if(insn[21] | !insn[24]) begin outstall = 1'b1; if(!rw_wait) next_lsr_state = 2'b10; @@ -186,6 +253,7 @@ module Memory( `DECODE_LDMSTM: if(!inbubble) begin outstall = rw_wait; next_outbubble = rw_wait; + data_size = 3'b100; case(lsm_state) 3'b001: begin // next_regs = insn[23] ? op1[15:0] : op1[0:15]; @@ -292,7 +360,7 @@ module Memory( st_read = cur_reg; wr_data = st_data; - busaddr = {raddr[31:2], 2'b0}; + busaddr = raddr; outstall = 1'b1;