signal overflow_32 : std_ulogic;
signal overflow_64 : std_ulogic;
- signal cmprb_result : std_ulogic_vector(3 downto 0);
- signal cmpeqb_result : std_ulogic_vector(3 downto 0);
signal trapval : std_ulogic_vector(4 downto 0);
+ signal write_cr_mask : std_ulogic_vector(7 downto 0);
+ signal write_cr_data : std_ulogic_vector(31 downto 0);
+
-- multiply signals
signal x_to_multiply: MultiplyInputType;
signal multiply_to_x: MultiplyOutputType;
begin
e.xerc.ca32 := carry32;
e.xerc.ca := carry;
- e.write_xerc_enable := '1';
end;
procedure set_ov(e: inout Execute1ToWritebackType;
if ov = '1' then
e.xerc.so := '1';
end if;
- e.write_xerc_enable := '1';
end;
function calc_ov(msb_a : std_ulogic; msb_b: std_ulogic;
variable darn : std_ulogic_vector(63 downto 0);
variable setb_result : std_ulogic_vector(63 downto 0);
variable mfcr_result : std_ulogic_vector(63 downto 0);
- variable crnum : crnum_t;
variable lo, hi : integer;
variable l : std_ulogic;
variable zerohi, zerolo : std_ulogic;
variable a_lt : std_ulogic;
variable a_lt_lo : std_ulogic;
variable a_lt_hi : std_ulogic;
- variable bfa : std_ulogic_vector(2 downto 0);
+ variable newcrf : std_ulogic_vector(3 downto 0);
+ variable bf, bfa : std_ulogic_vector(2 downto 0);
+ variable crnum : crnum_t;
+ variable scrnum : crnum_t;
+ variable cr_operands : std_ulogic_vector(1 downto 0);
+ variable crresult : std_ulogic;
+ variable bt, ba, bb : std_ulogic_vector(4 downto 0);
+ variable btnum : integer range 0 to 3;
+ variable banum, bbnum : integer range 0 to 31;
+ variable j : integer;
begin
-- Main adder
if e_in.invert_a = '0' then
end if;
end if;
- cmprb_result <= ppc_cmprb(a_in, b_in, insn_l(e_in.insn));
- cmpeqb_result <= ppc_cmpeqb(a_in, b_in);
+ -- CR result mux
+ bf := insn_bf(e_in.insn);
+ crnum := to_integer(unsigned(bf));
+ newcrf := (others => '0');
+ case current.sub_select is
+ when "000" =>
+ -- CMP and CMPL instructions
+ if e_in.is_signed = '1' then
+ newcrf := trapval(4 downto 2) & xerc_in.so;
+ else
+ newcrf := trapval(1 downto 0) & trapval(2) & xerc_in.so;
+ end if;
+ when "001" =>
+ newcrf := ppc_cmprb(a_in, b_in, insn_l(e_in.insn));
+ when "010" =>
+ newcrf := ppc_cmpeqb(a_in, b_in);
+ when "011" =>
+ if current.insn(1) = '1' then
+ -- CR logical instructions
+ j := (7 - crnum) * 4;
+ newcrf := cr_in(j + 3 downto j);
+ bt := insn_bt(e_in.insn);
+ ba := insn_ba(e_in.insn);
+ bb := insn_bb(e_in.insn);
+ btnum := 3 - to_integer(unsigned(bt(1 downto 0)));
+ banum := 31 - to_integer(unsigned(ba));
+ bbnum := 31 - to_integer(unsigned(bb));
+ -- Bits 6-9 of the instruction word give the truth table
+ -- of the requested logical operation
+ cr_operands := cr_in(banum) & cr_in(bbnum);
+ crresult := e_in.insn(6 + to_integer(unsigned(cr_operands)));
+ for i in 0 to 3 loop
+ if i = btnum then
+ newcrf(i) := crresult;
+ end if;
+ end loop;
+ else
+ -- MCRF
+ bfa := insn_bfa(e_in.insn);
+ scrnum := to_integer(unsigned(bfa));
+ j := (7 - scrnum) * 4;
+ newcrf := cr_in(j + 3 downto j);
+ end if;
+ when "100" =>
+ -- MCRXRX
+ newcrf := xerc_in.ov & xerc_in.ca & xerc_in.ov32 & xerc_in.ca32;
+ when others =>
+ end case;
+ if current.insn_type = OP_MTCRF then
+ if e_in.insn(20) = '0' then
+ -- mtcrf
+ write_cr_mask <= insn_fxm(e_in.insn);
+ else
+ -- mtocrf: We require one hot priority encoding here
+ crnum := fxm_to_num(insn_fxm(e_in.insn));
+ write_cr_mask <= num_to_fxm(crnum);
+ end if;
+ write_cr_data <= c_in(31 downto 0);
+ else
+ write_cr_mask <= num_to_fxm(crnum);
+ write_cr_data <= newcrf & newcrf & newcrf & newcrf &
+ newcrf & newcrf & newcrf & newcrf;
+ end if;
+
end process;
execute1_1: process(all)
variable v : reg_type;
- variable newcrf : std_ulogic_vector(3 downto 0);
- variable crnum : crnum_t;
- variable scrnum : crnum_t;
variable lo, hi : integer;
variable sh, mb, me : std_ulogic_vector(5 downto 0);
variable bo, bi : std_ulogic_vector(4 downto 0);
- variable bf, bfa : std_ulogic_vector(2 downto 0);
- variable cr_op : std_ulogic_vector(9 downto 0);
- variable cr_operands : std_ulogic_vector(1 downto 0);
- variable bt, ba, bb : std_ulogic_vector(4 downto 0);
- variable btnum, banum, bbnum : integer range 0 to 31;
- variable crresult : std_ulogic;
variable overflow : std_ulogic;
variable lv : Execute1ToLoadstore1Type;
variable irq_valid : std_ulogic;
variable f : Execute1ToFetch1Type;
variable fv : Execute1ToFPUType;
begin
- newcrf := (others => '0');
is_branch := '0';
is_direct_branch := '0';
taken_branch := '0';
else
v.e.xerc.ov := carry_64;
v.e.xerc.ov32 := carry_32;
- v.e.write_xerc_enable := '1';
end if;
end if;
if e_in.oe = '1' then
set_ov(v.e, overflow_64, overflow_32);
end if;
when OP_CMP =>
- -- CMP and CMPL instructions
- if e_in.is_signed = '1' then
- newcrf := trapval(4 downto 2) & xerc_in.so;
- else
- newcrf := trapval(1 downto 0) & trapval(2) & xerc_in.so;
- end if;
- bf := insn_bf(e_in.insn);
- crnum := to_integer(unsigned(bf));
- v.e.write_cr_mask := num_to_fxm(crnum);
- for i in 0 to 7 loop
- lo := i*4;
- hi := lo + 3;
- v.e.write_cr_data(hi downto lo) := newcrf;
- end loop;
when OP_TRAP =>
-- trap instructions (tw, twi, td, tdi)
v.vector := 16#700#;
end if;
when OP_ADDG6S =>
when OP_CMPRB =>
- newcrf := cmprb_result;
- bf := insn_bf(e_in.insn);
- crnum := to_integer(unsigned(bf));
- v.e.write_cr_mask := num_to_fxm(crnum);
- v.e.write_cr_data := newcrf & newcrf & newcrf & newcrf &
- newcrf & newcrf & newcrf & newcrf;
when OP_CMPEQB =>
- newcrf := cmpeqb_result;
- bf := insn_bf(e_in.insn);
- crnum := to_integer(unsigned(bf));
- v.e.write_cr_mask := num_to_fxm(crnum);
- v.e.write_cr_data := newcrf & newcrf & newcrf & newcrf &
- newcrf & newcrf & newcrf & newcrf;
when OP_AND | OP_OR | OP_XOR | OP_POPCNT | OP_PRTY | OP_CMPB | OP_EXTS |
OP_BPERM | OP_BCD =>
v.cntz_in_progress := '1';
v.busy := '1';
when OP_ISEL =>
- when OP_CROP =>
- cr_op := insn_cr(e_in.insn);
- if cr_op(0) = '0' then -- MCRF
- bf := insn_bf(e_in.insn);
- bfa := insn_bfa(e_in.insn);
- crnum := to_integer(unsigned(bf));
- scrnum := to_integer(unsigned(bfa));
- v.e.write_cr_mask := num_to_fxm(crnum);
- for i in 0 to 7 loop
- lo := (7-i)*4;
- hi := lo + 3;
- if i = scrnum then
- newcrf := cr_in(hi downto lo);
- end if;
- end loop;
- for i in 0 to 7 loop
- lo := i*4;
- hi := lo + 3;
- v.e.write_cr_data(hi downto lo) := newcrf;
- end loop;
- else
- bt := insn_bt(e_in.insn);
- ba := insn_ba(e_in.insn);
- bb := insn_bb(e_in.insn);
- btnum := 31 - to_integer(unsigned(bt));
- banum := 31 - to_integer(unsigned(ba));
- bbnum := 31 - to_integer(unsigned(bb));
- -- Bits 5-8 of cr_op give the truth table of the requested
- -- logical operation
- cr_operands := cr_in(banum) & cr_in(bbnum);
- crresult := cr_op(5 + to_integer(unsigned(cr_operands)));
- v.e.write_cr_mask := num_to_fxm((31-btnum) / 4);
- for i in 0 to 31 loop
- if i = btnum then
- v.e.write_cr_data(i) := crresult;
- else
- v.e.write_cr_data(i) := cr_in(i);
- end if;
- end loop;
- end if;
+ when OP_CROP =>
when OP_MCRXRX =>
- newcrf := xerc_in.ov & xerc_in.ca & xerc_in.ov32 & xerc_in.ca32;
- bf := insn_bf(e_in.insn);
- crnum := to_integer(unsigned(bf));
- v.e.write_cr_mask := num_to_fxm(crnum);
- v.e.write_cr_data := newcrf & newcrf & newcrf & newcrf &
- newcrf & newcrf & newcrf & newcrf;
when OP_DARN =>
when OP_MFMSR =>
when OP_MFSPR =>
when OP_MFCR =>
when OP_MTCRF =>
- if e_in.insn(20) = '0' then
- -- mtcrf
- v.e.write_cr_mask := insn_fxm(e_in.insn);
- else
- -- mtocrf: We require one hot priority encoding here
- crnum := fxm_to_num(insn_fxm(e_in.insn));
- v.e.write_cr_mask := num_to_fxm(crnum);
- end if;
- v.e.write_cr_data := c_in(31 downto 0);
when OP_MTMSRD =>
if e_in.insn(16) = '1' then
-- just update EE and RI
v.e.xerc.ca := c_in(63-34);
v.e.xerc.ov32 := c_in(63-44);
v.e.xerc.ca32 := c_in(63-45);
- v.e.write_xerc_enable := '1';
end if;
else
-- slow spr
v.mul_finish := '1';
v.busy := '1';
else
- v.e.write_xerc_enable := current.oe;
-- We must test oe because the RC update code in writeback
-- will use the xerc value to set CR0:SO so we must not clobber
-- xerc if OE wasn't set.
end if;
elsif r.mul_finish = '1' then
hold_wr_data := '1';
- v.e.write_xerc_enable := current.oe;
v.e.xerc.ov := multiply_to_x.overflow;
v.e.xerc.ov32 := multiply_to_x.overflow;
if multiply_to_x.overflow = '1' then
end if;
v.e.write_reg := current.write_reg;
v.e.write_enable := current.write_reg_enable and v.e.valid and not exception;
- v.e.write_cr_enable := current.output_cr and v.e.valid and not exception;
v.e.rc := current.rc and v.e.valid and not exception;
+ v.e.write_cr_data := write_cr_data;
+ v.e.write_cr_mask := write_cr_mask;
+ v.e.write_cr_enable := current.output_cr and v.e.valid and not exception;
+ v.e.write_xerc_enable := current.output_xer and v.e.valid and not exception;
bypass_data.tag.valid <= current.instr_tag.valid and current.write_reg_enable and v.e.valid;
bypass_data.tag.tag <= current.instr_tag.tag;
projects / microwatt.git / blobdiff