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Implement push rr

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This commit is contained in:
Koray Yanik 2021-02-23 22:38:10 +00:00
parent f6e68231fd
commit c8756dafa6
3 changed files with 29 additions and 12 deletions
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1
rtl/cpu/cpu.sv
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@ -114,6 +114,7 @@ module cpu (
);
assign alu_operand = (op_src == OP_SRC_A) ? rega :
(op_src == OP_SRC_F) ? regf :
(op_src == OP_SRC_OPERAND8) ? operand8 :
(op_src == OP_SRC_REG8) ? reg8_rdata :
(op_src == OP_SRC_MEMORY) ? rdata_i :

1
rtl/cpu/cpu_pkg.svh
View File

@ -63,6 +63,7 @@ package cpu_pkg;
typedef enum {
OP_SRC_A,
OP_SRC_F,
OP_SRC_REG8,
OP_SRC_OPERAND8,
OP_SRC_MEMORY,

39
rtl/cpu/decode.sv
View File

@ -62,9 +62,11 @@ module decode (
logic is_inc_r;
logic is_jr_cc_n;
logic is_call_nn;
logic is_push_rr;
reg8_t reg8_dest;
reg8_t reg8_src;
reg16_t reg16_src;
assign dec_x = instr0_i[7:6];
assign dec_y = instr0_i[5:3];
@ -95,23 +97,30 @@ module decode (
assign is_jr_cc_n = (dec_x == 2'h0) & (dec_z == 2'h0) & dec_y[2];
assign is_call_nn = (instr0_i == 8'hCD);
assign is_push_rr = (dec_x == 2'h3) & (dec_z == 3'h5) && ~dec_q;
assign reg8_src = is_cb ? reg8_t'(instr1_i[2:0]) :
is_ldh_c_a ? REG8_C :
is_inc_r ? reg8_t'(dec_y) :
reg8_t'(dec_z);
assign reg8_src = is_cb ? reg8_t'(instr1_i[2:0]) :
is_ldh_c_a ? REG8_C :
is_inc_r ? reg8_t'(dec_y) :
(is_push_rr & state_i == ST2_EXEC) ? reg8_t'({dec_p, 1'b0}) :
(is_push_rr & state_i == ST3_EXEC) ? reg8_t'({dec_p, 1'b1}) :
reg8_t'(dec_z);
assign reg8_dest = reg8_t'(dec_y);
assign reg16_src = is_ldd_hl_a ? REG16_HL : reg16_t'(dec_p);
assign need_instr1_o = is_ld_sp_nn | is_ld_rr_nn | is_ld_a_nn | is_call_nn | is_cb | is_jr_cc_n | is_ld_r_n | is_ldh_n_a;
assign need_instr2_o = is_ld_sp_nn | is_ld_rr_nn | is_ld_a_nn | is_call_nn;
assign is_multicycle_o = is_ld_a_rr | is_call_nn;
assign is_multicycle_o = is_ld_a_rr | is_call_nn | is_push_rr;
assign undef_o = ~(is_ldh_n_a | is_ld_r_r | is_ld_sp_nn | is_ld_rr_nn | is_alu_a_r | is_ldd_hl_a | is_bit_n_r |
is_jr_cc_n | is_ld_r_n | is_ldh_c_a | is_inc_r | is_ld_rr_a | is_ld_a_rr | is_call_nn);
is_jr_cc_n | is_ld_r_n | is_ldh_c_a | is_inc_r | is_ld_rr_a | is_ld_a_rr | is_call_nn |
is_push_rr);
assign sp_we_o = is_ld_sp_nn | is_call_nn;
assign sp_we_o = is_ld_sp_nn | is_call_nn | is_push_rr;
assign sp_src_o = is_ld_sp_nn ? SP_SRC_OPERAND16 :
is_call_nn ? SP_SRC_DEC :
is_push_rr ? SP_SRC_DEC :
sp_src_t'('X);
assign alu_op_valid_o = is_alu_a_r | is_bit_n_r | is_ld_a_n | is_ld_a_rr | is_ld_a_nn | is_inc_r;
@ -139,6 +148,7 @@ module decode (
is_inc_a ? OP_DEST_A :
is_inc_r ? OP_DEST_REG8 :
is_call_nn ? OP_DEST_MEMORY :
is_push_rr ? OP_DEST_MEMORY :
op_dest_t'('X);
assign op_src_o = (is_ld_r_r & reg8_src == REG8_A) ? OP_SRC_A :
@ -154,14 +164,17 @@ module decode (
is_ld_rr_nn ? OP_SRC_OPERAND16 :
is_ldd_hl_a ? OP_SRC_REG16 :
is_bit_n_r ? OP_SRC_REG8 :
is_call_nn & (state_i == ST4_EXEC) ? OP_SRC_PC_L :
is_call_nn & (state_i == ST5_EXEC) ? OP_SRC_PC_H :
(is_call_nn & state_i == ST4_EXEC) ? OP_SRC_PC_L :
(is_call_nn & state_i == ST5_EXEC) ? OP_SRC_PC_H :
(is_push_rr & reg16_src != REG16_SP_AF) ? OP_SRC_REG8 :
(is_push_rr & reg16_src == REG16_SP_AF & state_i == ST2_EXEC) ? OP_SRC_A :
(is_push_rr & reg16_src == REG16_SP_AF & state_i == ST3_EXEC) ? OP_SRC_F :
op_src_t'('X);
assign reg8_dest_o = reg8_dest;
assign reg8_src_o = reg8_src;
assign reg16_src_o = is_ldd_hl_a ? REG16_HL : reg16_t'(dec_p);
assign reg16_dest_o = is_ldd_hl_a ? REG16_HL : reg16_t'(dec_p);
assign reg16_src_o = reg16_src;
assign reg16_dest_o = reg16_src;
assign pc_src_o = is_jr_cc_n ? PC_SRC_OPERAND8 :
is_call_nn ? PC_SRC_OPERAND16 :
@ -178,11 +191,13 @@ module decode (
is_ld_a_rr ? ADR_SRC_REG16 :
is_ld_rr_a ? ADR_SRC_REG16 :
is_call_nn ? ADR_SRC_SP :
is_push_rr ? ADR_SRC_SP :
ADR_SRC_PC;
assign branch_always_o = is_call_nn;
assign cc_o = cc_t'(dec_y[1:0]);
assign memory_we_o = is_ldd_hl_a | is_ldh_c_a | is_ldh_n_a | is_ld_rr_a | (is_ld_r_n & reg8_dest == REG8_PHL) | (is_ld_r_r & reg8_dest == REG8_PHL) | is_call_nn;
assign memory_we_o = is_ldd_hl_a | is_ldh_c_a | is_ldh_n_a | is_ld_rr_a | (is_ld_r_n & reg8_dest == REG8_PHL) | (is_ld_r_r & reg8_dest == REG8_PHL) |
is_call_nn | is_push_rr;
endmodule : decode