diff options
author | jjsuperpower <jjs29356@gmail.com> | 2022-09-05 20:04:52 -0500 |
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committer | jjsuperpower <jjs29356@gmail.com> | 2022-09-05 20:04:52 -0500 |
commit | 63626f2f6fc7e8912a349f120e37998cd1a05554 (patch) | |
tree | a4a10c448613bd683b79a2f5dbef892edef0d49d /hdl/core | |
parent | 762e8b8786d8c921726c8ddc92a2513f42dad683 (diff) |
moveing file around
Diffstat (limited to 'hdl/core')
-rw-r--r-- | hdl/core/reg.py | 304 |
1 files changed, 0 insertions, 304 deletions
diff --git a/hdl/core/reg.py b/hdl/core/reg.py deleted file mode 100644 index b6aa3c5..0000000 --- a/hdl/core/reg.py +++ /dev/null @@ -1,304 +0,0 @@ -from amaranth import * -from amaranth.sim import Settle - -from hdl.lib.in_out_buff import InOutBuff -from hdl.utils import cmd, step, sim - -class Reg(Elaboratable): - def __init__(self, **kargs): # sim is only for modularity, does nothing for this - - ################ INPUTS ################ - self.wr_en = Signal(1) - self.stall = Signal(1) # stall instruction pointer increment - - self.rd = Signal(32) - self.rd_addr = Signal(4) - self.rs1_addr = Signal(4) - self.rs2_addr = Signal(4) - - self.alu_flgs = Signal(5) # flags from alu - - # these signals should be used one hot only - self.int_sig = Signal(1) # unconditional interrupt - self.iret = Signal(1) # return from interrupt - self.call = Signal(1) # call subroutine, save return address - self.jump = Signal(1) # jump, do not save return address - - - ################ OUTPUTS ################ - - self.rs1 = Signal(32) # read data 1 - self.rs2 = Signal(32) # read data 2 - - self.int_en = Signal(1) #interupt enable output signal to control unit - self.user_mode = Signal(1) # user mode output signal to control unit - - - ################ INTERNAL SIGNALS ################ - self._wr_alu_flg = Signal(1) - self._inc_ip = Signal(1) - - self.zx = Signal(32) #0 - self.ax = Signal(32) #1 - self.bx = Signal(32) #2 - self.bx = Signal(32) #3 - self.cx = Signal(32) #4 - self.dx = Signal(32) #5 - self.ex = Signal(32) #6 - self.fx = Signal(32) #7 - self.gx = Signal(32) #8 - self.hx = Signal(32) #9 - self.ip = Signal(32) #10 - self.sp = Signal(32) #11 - self.flg = Signal(32) #12 - self.cs0 = Signal(32) #13 - self.cs1 = Signal(32) #14 - self.cs2 = Signal(32) #15 - self.pda = Signal(32) #16 - - # for sake of modularity, make bit locations easily configurable - setattr(self.flg, 'c', self.flg[0]) - setattr(self.flg, 'ov', self.flg[1]) - setattr(self.flg, 'z', self.flg[2]) - setattr(self.flg, 'n', self.flg[3]) - setattr(self.flg, 'od', self.flg[4]) - setattr(self.flg, 'int', self.flg[16]) - setattr(self.flg, 'user_mode', self.flg[17]) - setattr(self.flg, 'page_en', self.flg[18]) - - - reg_list = [self.zx, self.ax, self.bx, self.cx, self.dx, self.ex, self.fx, self.gx, self.hx, self.ip, self.sp, self.flg, self.cs0, self.cs1, self.cs2, self.pda] - for idx, reg in enumerate(reg_list): - setattr(reg, 'idx', idx) # set idx attribute to each register - - self.reg_arr = Array(reg_list) - - ports_in = [self.wr_en, self.alu_flgs, self.int_sig, self.iret, self.call, self.jump, self.rd_addr, self.rd, self.rs1_addr, self.rs2_addr] - ports_out = [self.int_en, self.user_mode, self.rs1, self.rs2, self.ip] - self.ports = {'in': ports_in, 'out': ports_out} - - - def elaborate(self, platform=None): - m = Module() - - # output signals to control unit - m.d.comb += self.int_en.eq(self.flg.int) - m.d.comb += self.user_mode.eq(self.flg.user_mode & ~self.int_sig) - - # defualt value of internal signals - m.d.comb += self._wr_alu_flg.eq(1) - m.d.comb += self._inc_ip.eq(1) - - with m.If(self.int_sig): - m.d.comb += self._inc_ip.eq(0) - m.d.sync += self.ip.eq(self.rd) - m.d.sync += self.cs0.eq(self.ip) - m.d.sync += self.cs1.eq(self.sp) - m.d.sync += self.cs2.eq(self.flg) - m.d.sync += self.flg.user_mode.eq(0) # set to system mode or iret cannot be used - m.d.sync += self.flg.int.eq(0) # clear int flag, essential because another interrupt can be triggered without this - - with m.Elif(self.iret): - m.d.comb += self._inc_ip.eq(0) - m.d.sync += self.ip.eq(self.cs0) - m.d.sync += self.sp.eq(self.cs1) - m.d.sync += self.flg.eq(self.cs2) - - with m.Elif(self.call): - m.d.comb += self._inc_ip.eq(0) - m.d.sync += self.ip.eq(self.rd) - m.d.sync += self.cs0.eq(self.ip) - - with m.Elif(self.jump): - m.d.comb += self._inc_ip.eq(0) - m.d.sync += self.ip.eq(self.cs0) - - with m.Elif(self.wr_en): - with m.Switch(self.rd_addr): - with m.Case(self.zx.idx): # do not write to zero register - pass - - with m.Case(self.ip.idx): #do not directly write to ip register - pass - - with m.Case(self.flg.idx): - # mask top half of register to prevent writing to flags in user mode - with m.If(~self.flg.user_mode): - m.d.sync += self.flg.eq(self.rd) # system mode, full control - with m.Else(): - m.d.sync += self.flg.eq(Cat(self.rd[:16], self.flg[16:])) # usermode can only effect lower 16 bits - - # don't update flags from alu - m.d.comb += self._wr_alu_flg.eq(0) - - with m.Case(): - m.d.sync += self.reg_arr[self.rd_addr].eq(self.rd) - - with m.If(self._wr_alu_flg): # alu flags are written only if write enabled and not writing to flags register - m.d.sync += self.flg.eq(Cat(self.alu_flgs, self.flg[len(self.alu_flgs):])) - - - with m.If(self._inc_ip & ~self.stall): # increment ip if not directly writing to ip register - m.d.sync += self.ip.eq(self.ip + 4) - - - ### Combination signal outputs ### - with m.Switch(self.rs1_addr): - with m.Case(self.flg.idx): - m.d.comb += self.rs1.eq(self.flg & Cat(Const(0xFFFF, 16), Repl(~self.flg.user_mode, 16))) - with m.Case(): - m.d.comb += self.rs1.eq(self.reg_arr[self.rs1_addr]) - - with m.Switch(self.rs2_addr): - with m.Case(self.flg.idx): - m.d.comb += self.rs2.eq(self.flg & Cat(Const(0xFFFF, 16), Repl(~self.flg.user_mode, 16))) - with m.Case(): - m.d.comb += self.rs2.eq(self.reg_arr[self.rs2_addr]) - - return m - - -#--------------------------------- TEST BENCH BELOW ---------------------------------# - -def _init(dut): - for i in range(16): - yield dut.reg_arr[i].eq(i) - yield Settle() - - -# test combinational output -def test_reg_comb_output(): - dut = Reg() - def proc(): - yield from _init(dut) - for i in range(16): - yield dut.rs1_addr.eq(i) - yield Settle() - assert (yield dut.rs1) == i, f'ERROR reading {dut.reg_arr[i].name} != {i}' - for i in range(16): - yield dut.rs2_addr.eq(i) - yield Settle() - assert (yield dut.rs2) == i, f'ERROR reading {dut.reg_arr[i].name} != {i}' - sim(dut, proc) - -# test writeback with writeback disabled -def test_reg_writeback_dsb(): - dut = Reg() - def proc(): - yield from _init(dut) - for i in range(16): - yield dut.rd_addr.eq(i) - yield dut.rd.eq(i + 1) - yield from step() - if (i != dut.ip.idx) and (i != dut.flg.idx): # flag gets update by the alu - assert (yield dut.reg_arr[i]) == i, f'ERROR writing to {dut.reg_arr[i].name} != {i}' - sim(dut, proc) - -# test writeback with writeback enabled -def test_reg_writeback_en(): - dut = Reg() - def proc(): - for i in range(16): - yield from _init(dut) - yield dut.wr_en.eq(1) - yield dut.rd_addr.eq(i) - yield dut.rd.eq(i - 1) - yield from step() - if (i != dut.zx.idx) and (i != dut.ip.idx): - assert (yield dut.reg_arr[i]) == i-1, f'ERROR writing to {dut.reg_arr[i].name} != {i-1}' - elif i == dut.zx.idx: - assert (yield dut.zx) == 0, f'ERROR {dut.zx.name} != 0' - elif i == dut.ip.idx: - # ip should be incremented and not written to - assert (yield dut.reg_arr[i]) == i+1, f'ERROR {dut.ip.name} != {i + 1} should not be able to be directly written to' - sim(dut, proc) - -# check to make sure alu is writing values -def test_reg_flg_write_aluflg(): - dut = Reg() - def proc(): - yield dut.flg.eq(0) - yield dut.alu_flgs.eq(Repl(1, dut.alu_flgs.width)) - yield dut.wr_en.eq(1) - yield dut.flg.user_mode.eq(0) - yield dut.rd_addr.eq(dut.zx.idx) # can be anything except flg register - yield dut.rd.eq(0xFFFF0000) # this does not matter - yield from step() - assert (yield dut.flg) == (yield dut.alu_flgs), f'ERROR: alu is not writing to flg register' - sim(dut, proc) - -def test_reg_flg_overwrite(): - dut = Reg() - def proc(): - yield dut.flg.eq(0) - yield dut.alu_flgs.eq(Repl(1, dut.alu_flgs.width)) - yield dut.wr_en.eq(1) - yield dut.flg.user_mode.eq(0) - yield dut.flg[15].eq(1) - yield dut.flg[31].eq(1) - yield dut.rd_addr.eq(dut.flg.idx) - yield dut.rd.eq(0xFFFF0000) - yield from step() - assert (yield dut.flg) == (0xFFFF0000), f'ERROR: alu status should not be to flag' - sim(dut, proc) - -# test flag register security -def test_reg_flg_read_usermode(): - dut = Reg() - def proc(): - yield dut.flg.eq(0) - yield dut.flg.user_mode.eq(1) - yield dut.flg[15].eq(1) - yield dut.flg[31].eq(1) - yield dut.rs1_addr.eq(dut.flg.idx) - yield Settle() - assert (yield dut.rs1) == 0x00008000, f'ERROR: able to read upper 16 bits of flg reg in user mode' - sim(dut, proc) - -# test flag register security -def test_reg_flg_write_usermode(): - dut = Reg() - def proc(): - yield dut.flg.eq(0) - yield dut.wr_en.eq(1) - yield dut.flg.user_mode.eq(1) - yield dut.flg[15].eq(1) - yield dut.flg[31].eq(1) - yield dut.rd_addr.eq(dut.flg.idx) - yield dut.rd.eq(0xABCD5789) - yield from step() - assert (yield dut.flg) == (0x80020000 | 0x5789), f'ERROR: able to write to upper 16 bits of flg reg in user mode' - sim(dut, proc) - -def test_reg_flg_read_systemmode(): - dut = Reg() - def proc(): - yield dut.flg.eq(0) - yield dut.flg.user_mode.eq(0) - yield dut.flg[15].eq(1) - yield dut.flg[31].eq(1) - yield dut.rs1_addr.eq(dut.flg.idx) - yield Settle() - assert (yield dut.rs1) == 0x80008000, f'ERROR: able to read all bits of flg reg in system mode' - sim(dut, proc) - -# make sure not to write alu flags when directly writing to flg register -def test_reg_flg_write_systemmode(): - dut = Reg() - def proc(): - yield dut.flg.eq(0) - yield dut.wr_en.eq(1) - yield dut.flg.user_mode.eq(0) - yield dut.flg[15].eq(1) - yield dut.flg[31].eq(1) - yield dut.rd_addr.eq(dut.flg.idx) - yield dut.rd.eq(0xABCD5789) - yield from step() - assert (yield dut.flg) == (0xABCD5789), f'ERROR: unamble to write to all bits in supervisor mode' - sim(dut, proc) - - - -if __name__ == '__main__': - reg = InOutBuff(Reg()) - cmd(reg)
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