+++ /dev/null
-"""Computation Unit (aka "ALU Manager").
-
-Manages a Pipeline or FSM, ensuring that the start and end time are 100%
-monitored. At no time may the ALU proceed without this module notifying
-the Dependency Matrices. At no time is a result production "abandoned".
-This module blocks (indicates busy) starting from when it first receives
-an opcode until it receives notification that
-its result(s) have been successfully stored in the regfile(s)
-
-Documented at http://libre-soc.org/3d_gpu/architecture/compunit
-"""
-
-from nmigen.compat.sim import run_simulation, Settle
-from nmigen.cli import rtlil
-from nmigen import Module
-
-from openpower.decoder.power_enums import MicrOp
-
-from soc.experiment.compalu_multi import MultiCompUnit
-from soc.experiment.alu_hier import ALU, DummyALU
-from soc.fu.alu.alu_input_record import CompALUOpSubset
-
-
-def op_sim(dut, a, b, op, inv_a=0, imm=0, imm_ok=0, zero_a=0):
- yield dut.issue_i.eq(0)
- yield
- yield dut.src_i[0].eq(a)
- yield dut.src_i[1].eq(b)
- yield dut.oper_i.insn_type.eq(op)
- yield dut.oper_i.invert_in.eq(inv_a)
- yield dut.oper_i.imm_data.data.eq(imm)
- yield dut.oper_i.imm_data.ok.eq(imm_ok)
- yield dut.oper_i.zero_a.eq(zero_a)
- yield dut.issue_i.eq(1)
- yield
- yield dut.issue_i.eq(0)
- yield
- if not imm_ok or not zero_a:
- yield dut.rd.go_i.eq(0b11)
- while True:
- yield
- rd_rel_o = yield dut.rd.rel_o
- print ("rd_rel", rd_rel_o)
- if rd_rel_o:
- break
- yield dut.rd.go_i.eq(0)
- if len(dut.src_i) == 3:
- yield dut.rd.go_i.eq(0b100)
- while True:
- yield
- rd_rel_o = yield dut.rd.rel_o
- print ("rd_rel", rd_rel_o)
- if rd_rel_o:
- break
- yield dut.rd.go_i.eq(0)
-
- req_rel_o = yield dut.wr.rel_o
- result = yield dut.o_data
- print ("req_rel", req_rel_o, result)
- while True:
- req_rel_o = yield dut.wr.rel_o
- result = yield dut.o_data
- print ("req_rel", req_rel_o, result)
- if req_rel_o:
- break
- yield
- yield dut.wr.go_i[0].eq(1)
- yield Settle()
- result = yield dut.o_data
- yield
- print ("result", result)
- yield dut.wr.go_i[0].eq(0)
- yield
- return result
-
-
-def scoreboard_sim_dummy(dut):
- result = yield from op_sim(dut, 5, 2, MicrOp.OP_NOP, inv_a=0,
- imm=8, imm_ok=1)
- assert result == 5, result
-
- result = yield from op_sim(dut, 9, 2, MicrOp.OP_NOP, inv_a=0,
- imm=8, imm_ok=1)
- assert result == 9, result
-
-
-def scoreboard_sim(dut):
- result = yield from op_sim(dut, 5, 2, MicrOp.OP_ADD, inv_a=0,
- imm=8, imm_ok=1)
- assert result == 13
-
- result = yield from op_sim(dut, 5, 2, MicrOp.OP_ADD)
- assert result == 7
-
- result = yield from op_sim(dut, 5, 2, MicrOp.OP_ADD, inv_a=1)
- assert result == 65532
-
- result = yield from op_sim(dut, 5, 2, MicrOp.OP_ADD, zero_a=1,
- imm=8, imm_ok=1)
- assert result == 8
-
- result = yield from op_sim(dut, 5, 2, MicrOp.OP_ADD, zero_a=1)
- assert result == 2
-
- # test combinatorial zero-delay operation
- # In the test ALU, any operation other than ADD, MUL or SHR
- # is zero-delay, and do a subtraction.
- result = yield from op_sim(dut, 5, 2, MicrOp.OP_NOP)
- assert result == 3
-
-
-def test_compunit():
-
- m = Module()
- alu = ALU(16)
- dut = MultiCompUnit(16, alu, CompALUOpSubset)
- m.submodules.cu = dut
-
- vl = rtlil.convert(dut, ports=dut.ports())
- with open("test_compunit1.il", "w") as f:
- f.write(vl)
-
- run_simulation(m, scoreboard_sim(dut), vcd_name='test_compunit1.vcd')
-
-
-class CompUnitParallelTest:
- def __init__(self, dut):
- self.dut = dut
-
- # Operation cycle should not take longer than this:
- self.MAX_BUSY_WAIT = 50
-
- # Minimum duration in which issue_i will be kept inactive,
- # during which busy_o must remain low.
- self.MIN_BUSY_LOW = 5
-
- # Number of cycles to stall until the assertion of go.
- # One value, for each port. Can be zero, for no delay.
- self.RD_GO_DELAY = [0, 3]
-
- # store common data for the input operation of the processes
- # input operation:
- self.op = 0
- self.inv_a = self.zero_a = 0
- self.imm = self.imm_ok = 0
- self.imm_control = (0, 0)
- self.rdmaskn = (0, 0)
- # input data:
- self.operands = (0, 0)
-
- # Indicates completion of the sub-processes
- self.rd_complete = [False, False]
-
- def driver(self):
- print("Begin parallel test.")
- yield from self.operation(5, 2, MicrOp.OP_ADD)
-
- def operation(self, a, b, op, inv_a=0, imm=0, imm_ok=0, zero_a=0,
- rdmaskn=(0, 0)):
- # store data for the operation
- self.operands = (a, b)
- self.op = op
- self.inv_a = inv_a
- self.imm = imm
- self.imm_ok = imm_ok
- self.zero_a = zero_a
- self.imm_control = (zero_a, imm_ok)
- self.rdmaskn = rdmaskn
-
- # Initialize completion flags
- self.rd_complete = [False, False]
-
- # trigger operation cycle
- yield from self.issue()
-
- # check that the sub-processes completed, before the busy_o cycle ended
- for completion in self.rd_complete:
- assert completion
-
- def issue(self):
- # issue_i starts inactive
- yield self.dut.issue_i.eq(0)
-
- for n in range(self.MIN_BUSY_LOW):
- yield
- # busy_o must remain inactive. It cannot rise on its own.
- busy_o = yield self.dut.busy_o
- assert not busy_o
-
- # activate issue_i to begin the operation cycle
- yield self.dut.issue_i.eq(1)
-
- # at the same time, present the operation
- yield self.dut.oper_i.insn_type.eq(self.op)
- yield self.dut.oper_i.invert_in.eq(self.inv_a)
- yield self.dut.oper_i.imm_data.imm.eq(self.imm)
- yield self.dut.oper_i.imm_data.imm_ok.eq(self.imm_ok)
- yield self.dut.oper_i.zero_a.eq(self.zero_a)
- rdmaskn = self.rdmaskn[0] | (self.rdmaskn[1] << 1)
- yield self.dut.rdmaskn.eq(rdmaskn)
-
- # give one cycle for the CompUnit to latch the data
- yield
-
- # busy_o must keep being low in this cycle, because issue_i was
- # low on the previous cycle.
- # It cannot rise on its own.
- # Also, busy_o and issue_i must never be active at the same time, ever.
- busy_o = yield self.dut.busy_o
- assert not busy_o
-
- # Lower issue_i
- yield self.dut.issue_i.eq(0)
-
- # deactivate inputs along with issue_i, so we can be sure the data
- # was latched at the correct cycle
- # note: rdmaskn must be held, while busy_o is active
- # TODO: deactivate rdmaskn when the busy_o cycle ends
- yield self.dut.oper_i.insn_type.eq(0)
- yield self.dut.oper_i.invert_in.eq(0)
- yield self.dut.oper_i.imm_data.imm.eq(0)
- yield self.dut.oper_i.imm_data.imm_ok.eq(0)
- yield self.dut.oper_i.zero_a.eq(0)
- yield
-
- # wait for busy_o to lower
- # timeout after self.MAX_BUSY_WAIT cycles
- for n in range(self.MAX_BUSY_WAIT):
- # sample busy_o in the current cycle
- busy_o = yield self.dut.busy_o
- if not busy_o:
- # operation cycle ends when busy_o becomes inactive
- break
- yield
-
- # if busy_o is still active, a timeout has occurred
- # TODO: Uncomment this, once the test is complete:
- # assert not busy_o
-
- if busy_o:
- print("If you are reading this, "
- "it's because the above test failed, as expected,\n"
- "with a timeout. It must pass, once the test is complete.")
- return
-
- print("If you are reading this, "
- "it's because the above test unexpectedly passed.")
-
- def rd(self, rd_idx):
- # wait for issue_i to rise
- while True:
- issue_i = yield self.dut.issue_i
- if issue_i:
- break
- # issue_i has not risen yet, so rd must keep low
- rel = yield self.dut.rd.rel_o[rd_idx]
- assert not rel
- yield
-
- # we do not want rd to rise on an immediate operand
- # if it is immediate, exit the process
- # likewise, if the read mask is active
- # TODO: don't exit the process, monitor rd instead to ensure it
- # doesn't rise on its own
- if self.rdmaskn[rd_idx] or self.imm_control[rd_idx]:
- self.rd_complete[rd_idx] = True
- return
-
- # issue_i has risen. rel must rise on the next cycle
- rel = yield self.dut.rd.rel_o[rd_idx]
- assert not rel
-
- # stall for additional cycles. Check that rel doesn't fall on its own
- for n in range(self.RD_GO_DELAY[rd_idx]):
- yield
- rel = yield self.dut.rd.rel_o[rd_idx]
- assert rel
-
- # Before asserting "go", make sure "rel" has risen.
- # The use of Settle allows "go" to be set combinatorially,
- # rising on the same cycle as "rel".
- yield Settle()
- rel = yield self.dut.rd.rel_o[rd_idx]
- assert rel
-
- # assert go for one cycle, passing along the operand value
- yield self.dut.rd.go_i[rd_idx].eq(1)
- yield self.dut.src_i[rd_idx].eq(self.operands[rd_idx])
- # check that the operand was sent to the alu
- # TODO: Properly check the alu protocol
- yield Settle()
- alu_input = yield self.dut.get_in(rd_idx)
- assert alu_input == self.operands[rd_idx]
- yield
-
- # rel must keep high, since go was inactive in the last cycle
- rel = yield self.dut.rd.rel_o[rd_idx]
- assert rel
-
- # finish the go one-clock pulse
- yield self.dut.rd.go_i[rd_idx].eq(0)
- yield self.dut.src_i[rd_idx].eq(0)
- yield
-
- # rel must have gone low in response to go being high
- # on the previous cycle
- rel = yield self.dut.rd.rel_o[rd_idx]
- assert not rel
-
- self.rd_complete[rd_idx] = True
-
- # TODO: check that rel doesn't rise again until the end of the
- # busy_o cycle
-
- def wr(self, wr_idx):
- # monitor self.dut.wr.req[rd_idx] and sets dut.wr.go[idx] for one cycle
- yield
- # TODO: also when dut.wr.go is set, check the output against the
- # self.expected_o and assert. use dut.get_out(wr_idx) to do so.
-
- def run_simulation(self, vcd_name):
- run_simulation(self.dut, [self.driver(),
- self.rd(0), # one read port (a)
- self.rd(1), # one read port (b)
- self.wr(0), # one write port (o)
- ],
- vcd_name=vcd_name)
-
-
-def test_compunit_regspec3():
-
- inspec = [('INT', 'a', '0:15'),
- ('INT', 'b', '0:15'),
- ('INT', 'c', '0:15')]
- outspec = [('INT', 'o', '0:15'),
- ]
-
- regspec = (inspec, outspec)
-
- m = Module()
- alu = DummyALU(16)
- dut = MultiCompUnit(regspec, alu, CompALUOpSubset)
- m.submodules.cu = dut
-
- run_simulation(m, scoreboard_sim_dummy(dut),
- vcd_name='test_compunit_regspec3.vcd')
-
-
-def test_compunit_regspec1():
-
- inspec = [('INT', 'a', '0:15'),
- ('INT', 'b', '0:15')]
- outspec = [('INT', 'o', '0:15'),
- ]
-
- regspec = (inspec, outspec)
-
- m = Module()
- alu = ALU(16)
- dut = MultiCompUnit(regspec, alu, CompALUOpSubset)
- m.submodules.cu = dut
-
- vl = rtlil.convert(dut, ports=dut.ports())
- with open("test_compunit_regspec1.il", "w") as f:
- f.write(vl)
-
- run_simulation(m, scoreboard_sim(dut),
- vcd_name='test_compunit_regspec1.vcd')
-
- test = CompUnitParallelTest(dut)
- test.run_simulation("test_compunit_parallel.vcd")
-
-
-if __name__ == '__main__':
- test_compunit()
- test_compunit_regspec1()
- test_compunit_regspec3()
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