load : std_ulogic;
tlbie : std_ulogic;
dcbz : std_ulogic;
- mfspr : std_ulogic;
addr : std_ulogic_vector(63 downto 0);
store_data : std_ulogic_vector(63 downto 0);
load_data : std_ulogic_vector(63 downto 0);
ld_sp_nz : std_ulogic;
ld_sp_lz : std_ulogic_vector(5 downto 0);
st_sp_data : std_ulogic_vector(31 downto 0);
+ wr_sel : std_ulogic_vector(1 downto 0);
end record;
signal r, rin : reg_stage_t;
variable itlb_fault : std_ulogic;
variable misaligned : std_ulogic;
variable fp_reg_conv : std_ulogic;
- variable lfs_done : std_ulogic;
begin
v := r;
req := '0';
- v.mfspr := '0';
mmu_mtspr := '0';
itlb_fault := '0';
sprn := std_ulogic_vector(to_unsigned(decode_spr_num(l_in.insn), 10));
dsisr := (others => '0');
mmureq := '0';
fp_reg_conv := '0';
+ v.wr_sel := "11";
write_enable := '0';
- lfs_done := '0';
do_update := r.do_update;
v.do_update := '0';
v.last_dword := '0';
when ACK_WAIT =>
+ -- r.wr_sel gets set one cycle after we come into ACK_WAIT state,
+ -- which is OK because the dcache always takes at least two cycles.
+ if r.update = '1' and (r.load = '0' or (HAS_FPU and r.load_sp = '1')) then
+ v.wr_sel := "01";
+ end if;
if d_in.error = '1' then
-- dcache will discard the second request if it
-- gets an error on the 1st of two requests
-- SP to DP conversion takes a cycle
-- Write back rA update in this cycle if needed
do_update := r.update;
+ v.wr_sel := "10";
v.state := FINISH_LFS;
elsif r.extra_cycle = '1' then
-- loads with rA update need an extra cycle
+ v.wr_sel := "01";
v.state := COMPLETE;
v.do_update := r.update;
else
when TLBIE_WAIT =>
when FINISH_LFS =>
- lfs_done := '1';
when COMPLETE =>
exception := r.align_intr;
v.state := TLBIE_WAIT;
v.wait_mmu := '1';
when OP_MFSPR =>
- v.mfspr := '1';
+ v.wr_sel := "00";
-- partial decode on SPR number should be adequate given
-- the restricted set that get sent down this path
if sprn(9) = '0' and sprn(5) = '0' then
-- Multiplex either cache data to the destination GPR or
-- the address for the rA update.
l_out.valid <= done;
- if r.mfspr = '1' then
+ case r.wr_sel is
+ when "00" =>
l_out.write_enable <= '1';
l_out.write_reg <= r.write_reg;
l_out.write_data <= r.sprval;
- elsif do_update = '1' then
- l_out.write_enable <= '1';
+ when "01" =>
+ l_out.write_enable <= do_update;
l_out.write_reg <= gpr_to_gspr(r.update_reg);
l_out.write_data <= r.addr;
- elsif lfs_done = '1' then
+ when "10" =>
l_out.write_enable <= '1';
l_out.write_reg <= r.write_reg;
l_out.write_data <= load_dp_data;
- else
+ when others =>
l_out.write_enable <= write_enable;
l_out.write_reg <= r.write_reg;
l_out.write_data <= data_trimmed;
- end if;
+ end case;
l_out.xerc <= r.xerc;
l_out.rc <= r.rc and done;
l_out.store_done <= d_in.store_done;