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Implemented LDD (HL), A

This commit is contained in:
Koray Yanik 2021-02-18 23:22:26 +00:00
parent 3e92cf5eec
commit 8f0b8d3a48
7 changed files with 92 additions and 22 deletions
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17
rtl/cpu/alu.sv
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@ -10,8 +10,14 @@ module alu (
input alu_op_t alu_op_i,
input logic [7:0] operand_i,
input alu16_op_t alu16_op_i,
input logic [15:0] inx16_i,
input logic [15:0] iny16_i,
output logic [ 7:0] a_o,
output logic [ 7:0] f_o
output logic [ 7:0] f_o,
output logic [15:0] out16_o
);
logic a_we;
@ -25,6 +31,11 @@ module alu (
logic [ 7:0] a_xor;
logic [ 7:0] f_xor;
logic [16:0] out16_add;
logic [ 7:0] f16_add;
logic [15:0] out16_inc;
logic [15:0] out16_dec;
`DEF_FF(a_r, a_next, a_we, '0);
`DEF_FF(f_r, f_next, f_we, '0);
@ -39,7 +50,11 @@ module alu (
assign a_xor = (a_r ^ operand_i);
assign f_xor = {~(|a_xor), 3'b0, f_r[3:0]};
assign out16_dec = (inx16_i - 16'h01);
assign a_o = a_r;
assign f_o = f_r;
assign out16_o = out16_dec;
endmodule : alu

13
rtl/cpu/control.sv
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@ -22,8 +22,11 @@ module control (
output alu_op_t alu_op_o,
output op_src_t op_src_o,
output op_dest_t op_dest_o,
output alu16_op_t alu16_op_o,
output reg16_t reg16_src_o,
output reg16_t reg16_dest_o,
output logic memory_we_o,
output adr_src_t adr_src_o
);
@ -64,6 +67,7 @@ module control (
logic decoder_need_instr1;
logic decoder_need_instr2;
logic decoder_is_undef;
logic decoder_memory_we;
adr_src_t decoder_adr_src;
logic is_undef;
@ -132,7 +136,11 @@ module control (
.op_src_o (op_src_o),
.op_dest_o (op_dest_o),
.alu16_op_o (alu16_op_o),
.reg16_src_o (reg16_src_o),
.reg16_dest_o (reg16_dest_o),
.memory_we_o (decoder_memory_we),
.adr_src_o (decoder_adr_src)
);
@ -155,7 +163,8 @@ module control (
assign operand8_o = operand0_r;
assign operand16_o = {operand1_r, operand0_r};
assign adr_src_o = (state_r == ST2_EXEC) | (state_r == ST4_EXEC) ? decoder_adr_src :
ADR_SRC_PC;
assign memory_we_o = ((state_r == ST2_EXEC) | (state_r == ST4_EXEC)) & decoder_memory_we;
assign adr_src_o = (state_r == ST2_EXEC) | (state_r == ST4_EXEC) ? decoder_adr_src :
ADR_SRC_PC;
endmodule : control

37
rtl/cpu/cpu.sv
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@ -7,7 +7,9 @@ module cpu (
input logic nreset_i,
output logic [15:0] address_o,
input logic [ 7:0] rdata_i
input logic [ 7:0] rdata_i,
output logic we_o,
output logic [ 7:0] wdata_o
);
state_t state;
@ -16,6 +18,7 @@ module cpu (
alu_op_t alu_op;
op_src_t op_src;
op_dest_t op_dest;
adr_src_t adr_src;
logic [ 7:0] alu_operand;
@ -24,6 +27,7 @@ module cpu (
logic [15:0] pc;
logic [15:0] sp;
logic [15:0] hl;
logic instr_valid;
logic instr_undef;
@ -39,8 +43,12 @@ module cpu (
logic [15:0] reg16_wdata;
reg8_t reg8_rselect;
reg16_t reg16_rselect;
reg16_t reg16_rselect2;
logic [ 7:0] reg8_rdata;
logic [15:0] reg16_rdata;
logic [15:0] reg16_rdata2;
alu16_op_t alu16_op;
logic [15:0] alu_out16;
control control_inst (
.clk_i (clk_i),
@ -57,7 +65,11 @@ module cpu (
.instr_undef_o (instr_undef),
.operand8_o (operand8),
.operand16_o (operand16),
.reg16_dest_o (reg16_wselect)
.alu16_op_o (alu16_op),
.reg16_src_o (reg16_rselect),
.reg16_dest_o (reg16_wselect),
.memory_we_o (we_o),
.adr_src_o (adr_src)
);
alu alu_inst (
@ -67,7 +79,11 @@ module cpu (
.alu_op_i (alu_op),
.operand_i (alu_operand),
.a_o (rega),
.f_o (regf)
.f_o (regf),
.alu16_op_i (alu16_op),
.inx16_i (reg16_rdata2),
.iny16_i (reg16_rdata),
.out16_o (alu_out16)
);
registers registers_inst (
@ -83,7 +99,10 @@ module cpu (
.reg8_rselect_i (reg8_rselect),
.reg8_rdata_o (reg8_rdata),
.reg16_rselect_i(reg16_rselect),
.reg16_rdata_o (reg16_rdata)
.reg16_rdata_o (reg16_rdata),
.reg16_rselect2_i(reg16_rselect2),
.reg16_rdata2_o (reg16_rdata2),
.hl_o (hl)
);
assign alu_operand = (op_src == OP_SRC_A) ? rega :
@ -92,11 +111,13 @@ module cpu (
assign reg8_wselect = reg8_t'('X);
assign reg8_we = '0;
assign reg8_wdata = operand8;
assign reg16_we = instr_valid & (op_dest == OP_DEST_R16);
assign reg16_wdata = operand16;
assign reg16_we = instr_valid & (op_dest == OP_DEST_REG16);
assign reg16_wdata = (op_src == OP_SRC_OPERAND16) ? operand16 : alu_out16;
assign reg8_rselect = reg8_t'('X);
assign reg16_rselect = reg16_t'('X);
assign reg16_rselect2 = reg16_wselect;
assign address_o = pc;
assign address_o = (adr_src == ADR_SRC_HL) ? hl :
pc;
assign wdata_o = rega;
endmodule : cpu

11
rtl/cpu/cpu_pkg.svh
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@ -40,15 +40,22 @@ package cpu_pkg;
ALU_OP_CP = 3'h07
} alu_op_t;
typedef enum logic [1:0] {
ALU16_OP_ADD = 2'h00,
ALU16_INC = 2'h01,
ALU16_DEC = 2'h02
} alu16_op_t;
typedef enum {
OP_SRC_A,
OP_SRC_REG8,
OP_SRC_OPERAND16
OP_SRC_OPERAND16,
OP_SRC_REG16
} op_src_t;
typedef enum {
OP_DEST_A,
OP_DEST_R16
OP_DEST_REG16
} op_dest_t;
typedef enum {

23
rtl/cpu/decode.sv
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@ -21,9 +21,12 @@ module decode (
output op_src_t op_src_o,
output op_dest_t op_dest_o,
output alu16_op_t alu16_op_o,
output reg16_t reg16_dest_o,
output reg16_t reg16_src_o,
output adr_src_t adr_src_o
output adr_src_t adr_src_o,
output logic memory_we_o
);
logic [1:0] dec_x;
@ -34,6 +37,7 @@ module decode (
logic is_ld_rr_nnnn;
logic is_ld_sp_nnnn;
logic is_ldd_hl_a;
logic is_alu_a_n;
assign dec_x = instr0_i[7:6];
@ -44,28 +48,35 @@ module decode (
assign is_ld_rr_nnnn = (dec_x == 2'h0) & (dec_z == 3'h1) & ~dec_q & (dec_p != 2'h3);
assign is_ld_sp_nnnn = (dec_x == 2'h0) & (dec_z == 3'h1) & ~dec_q & (dec_p == 2'h3);
assign is_ldd_hl_a = (dec_x == 2'h0) & (dec_z == 3'h2) & ~dec_q & (dec_p == 2'h3);
assign is_alu_a_n = (dec_x == 3'h2);
assign need_instr1_o = is_ld_sp_nnnn | is_ld_rr_nnnn;
assign need_instr2_o = is_ld_sp_nnnn | is_ld_rr_nnnn;
assign undef_o = ~(is_ld_sp_nnnn | is_ld_rr_nnnn | is_alu_a_n);
assign undef_o = ~(is_ld_sp_nnnn | is_ld_rr_nnnn | is_alu_a_n | is_ldd_hl_a);
assign sp_we_o = is_ld_sp_nnnn & (state_i == ST4_EXEC);
assign alu_op_valid_o = is_alu_a_n;
assign alu_op_o = alu_op_t'(dec_y);
assign op_dest_o = is_alu_a_n ? OP_DEST_A :
is_ld_rr_nnnn ? OP_DEST_R16 :
assign op_dest_o = is_alu_a_n ? OP_DEST_A :
is_ld_rr_nnnn ? OP_DEST_REG16 :
is_ldd_hl_a ? OP_DEST_REG16 :
op_dest_t'('X);
assign op_src_o = is_alu_a_n ? OP_SRC_REG8 :
is_ld_rr_nnnn ? OP_SRC_OPERAND16 :
is_ldd_hl_a ? OP_SRC_REG16 :
op_src_t'('X);
assign reg16_dest_o = reg16_t'(dec_p);
assign reg16_src_o = is_ldd_hl_a ? REG16_HL : reg16_t'(dec_p);
assign reg16_dest_o = is_ldi_hl_a ? REG16_HL : reg16_t'(dec_p);
assign adr_src_o = ADR_SRC_PC;
assign adr_src_o = is_ldi_hl_a ? ADR_SRC_HL :
ADR_SRC_PC;
assign memory_we_o = is_ldi_hl_a;
endmodule : decode

11
rtl/cpu/registers.sv
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@ -16,8 +16,12 @@ module registers (
input reg8_t reg8_rselect_i,
input reg16_t reg16_rselect_i,
input reg16_t reg16_rselect2_i,
output logic [ 7:0] reg8_rdata_o,
output logic [15:0] reg16_rdata_o
output logic [15:0] reg16_rdata_o,
output logic [15:0] reg16_rdata2_o,
output logic [15:0] hl_o
);
logic [15:0] reg_r [0:2];
@ -44,6 +48,9 @@ module registers (
assign reg8_rdata_o = reg8_rselect_i[0] ? reg_r[reg8_rselect_i[2:1]][15:8] :
reg_r[reg8_rselect_i[2:1]][ 7:0];
assign reg16_rdata_o = reg_r[reg16_rselect_i];
assign reg16_rdata_o = reg_r[reg16_rselect_i];
assign reg16_rdata2_o = reg_r[reg16_rselect2_i];
assign hl_o = reg_r[REG16_HL];
endmodule : registers

2
rtl/shared/rom.sv
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@ -18,7 +18,7 @@ always_ff @(posedge clk_i)
initial begin
static integer fd = $fopen(FILE_NAME, "rb");
void'($fread(rom, fd));
static integer rv = $fread(rom, fd);
end
endmodule : rom