1 """LOAD / STORE Computation Unit.
3 This module covers POWER9-compliant Load and Store operations,
4 with selection on each between immediate and indexed mode as
5 options for the calculation of the Effective Address (EA),
6 and also "update" mode which optionally stores that EA into
7 an additional register.
10 Note: it took 15 attempts over several weeks to redraw the diagram
11 needed to capture this FSM properly. To understand it fully, please
12 take the time to review the links, video, and diagram.
15 Stores are activated when Go_Store is enabled, and use a sync'd "ADD" to
16 compute the "Effective Address", and, when ready the operand (src3_i)
17 is stored in the computed address (passed through to the PortInterface)
19 Loads are activated when Go_Write[0] is enabled. The EA is computed,
20 and (as long as there was no exception) the data comes out (at any
21 time from the PortInterface), and is captured by the LDCompSTUnit.
23 Both LD and ST may request that the address be computed from summing
24 operand1 (src[0]) with operand2 (src[1]) *or* by summing operand1 with
25 the immediate (from the opcode).
27 Both LD and ST may also request "update" mode (op_is_update) which
28 activates the use of Go_Write[1] to control storage of the EA into
29 a *second* operand in the register file.
31 Thus this module has *TWO* write-requests to the register file and
32 *THREE* read-requests to the register file (not all at the same time!)
33 The regfile port usage is:
45 It's a multi-level Finite State Machine that (unfortunately) nmigen.FSM
46 is not suited to (nmigen.FSM is clock-driven, and some aspects of
47 the nested FSMs below are *combinatorial*).
49 * One FSM covers Operand collection and communication address-side
50 with the LD/ST PortInterface. its role ends when "RD_DONE" is asserted
52 * A second FSM activates to cover LD. it activates if op_is_ld is true
54 * A third FSM activates to cover ST. it activates if op_is_st is true
56 * The "overall" (fourth) FSM coordinates the progression and completion
57 of the three other FSMs, firing "WR_RESET" which switches off "busy"
61 https://libre-soc.org/3d_gpu/ld_st_comp_unit.jpg
63 Links including to walk-through videos:
65 * https://libre-soc.org/3d_gpu/architecture/6600scoreboard/
66 * http://libre-soc.org/openpower/isa/fixedload
67 * http://libre-soc.org/openpower/isa/fixedstore
71 * https://bugs.libre-soc.org/show_bug.cgi?id=302
72 * https://bugs.libre-soc.org/show_bug.cgi?id=216
76 * EA - Effective Address
81 from nmigen
.compat
.sim
import run_simulation
82 from nmigen
.cli
import verilog
, rtlil
83 from nmigen
import Module
, Signal
, Mux
, Cat
, Elaboratable
, Array
, Repl
84 from nmigen
.hdl
.rec
import Record
, Layout
86 from nmutil
.latch
import SRLatch
, latchregister
87 from nmutil
.byterev
import byte_reverse
89 from soc
.experiment
.compalu_multi
import go_record
, CompUnitRecord
90 from soc
.experiment
.l0_cache
import PortInterface
91 from soc
.fu
.regspec
import RegSpecAPI
93 from soc
.decoder
.power_enums
import MicrOp
, Function
, LDSTMode
94 from soc
.fu
.ldst
.ldst_input_record
import CompLDSTOpSubset
95 from soc
.decoder
.power_decoder2
import Data
98 class LDSTCompUnitRecord(CompUnitRecord
):
99 def __init__(self
, rwid
, opsubset
=CompLDSTOpSubset
, name
=None):
100 CompUnitRecord
.__init
__(self
, opsubset
, rwid
,
101 n_src
=3, n_dst
=2, name
=name
)
103 self
.ad
= go_record(1, name
="cu_ad") # address go in, req out
104 self
.st
= go_record(1, name
="cu_st") # store go in, req out
106 self
.addr_exc_o
= Signal(reset_less
=True) # address exception
108 self
.ld_o
= Signal(reset_less
=True) # operation is a LD
109 self
.st_o
= Signal(reset_less
=True) # operation is a ST
111 # hmm... are these necessary?
112 self
.load_mem_o
= Signal(reset_less
=True) # activate memory LOAD
113 self
.stwd_mem_o
= Signal(reset_less
=True) # activate memory STORE
116 class LDSTCompUnit(RegSpecAPI
, Elaboratable
):
117 """LOAD / STORE Computation Unit
122 * :pi: a PortInterface to the memory subsystem (read-write capable)
123 * :rwid: register width
124 * :awid: address width
128 * :src_i: Source Operands (RA/RB/RC) - managed by rd[0-3] go/req
132 * :data_o: Dest out (LD) - managed by wr[0] go/req
133 * :addr_o: Address out (LD or ST) - managed by wr[1] go/req
134 * :addr_exc_o: Address/Data Exception occurred. LD/ST must terminate
136 TODO: make addr_exc_o a data-type rather than a single-bit signal
142 * :oper_i: operation being carried out (POWER9 decode LD/ST subset)
143 * :issue_i: LD/ST is being "issued".
144 * :shadown_i: Inverted-shadow is being held (stops STORE *and* WRITE)
145 * :go_rd_i: read is being actioned (latches in src regs)
146 * :go_wr_i: write mode (exactly like ALU CompUnit)
147 * :go_ad_i: address is being actioned (triggers actual mem LD)
148 * :go_st_i: store is being actioned (triggers actual mem STORE)
149 * :go_die_i: resets the unit back to "wait for issue"
151 Control Signals (Out)
152 ---------------------
154 * :busy_o: function unit is busy
155 * :rd_rel_o: request src1/src2
156 * :adr_rel_o: request address (from mem)
157 * :sto_rel_o: request store (to mem)
158 * :req_rel_o: request write (result)
159 * :load_mem_o: activate memory LOAD
160 * :stwd_mem_o: activate memory STORE
162 Note: load_mem_o, stwd_mem_o and req_rel_o MUST all be acknowledged
163 in a single cycle and the CompUnit set back to doing another op.
164 This means deasserting go_st_i, go_ad_i or go_wr_i as appropriate
165 depending on whether the operation is a ST or LD.
167 Note: LDSTCompUnit takes care of LE/BE normalisation:
168 * LD data is normalised after receipt from the PortInterface
169 * ST data is normalised *prior* to sending onto the PortInterface
170 TODO: use one module for the byte-reverse as it's quite expensive in gates
173 def __init__(self
, pi
=None, rwid
=64, awid
=48, opsubset
=CompLDSTOpSubset
,
174 debugtest
=False, name
=None):
175 super().__init
__(rwid
)
178 self
.cu
= cu
= LDSTCompUnitRecord(rwid
, opsubset
, name
=name
)
179 self
.debugtest
= debugtest
181 # POWER-compliant LD/ST has index and update: *fixed* number of ports
182 self
.n_src
= n_src
= 3 # RA, RB, RT/RS
183 self
.n_dst
= n_dst
= 2 # RA, RT/RS
185 # set up array of src and dest signals
186 for i
in range(n_src
):
187 j
= i
+ 1 # name numbering to match src1/src2
189 setattr(self
, name
, getattr(cu
, name
))
192 for i
in range(n_dst
):
193 j
= i
+ 1 # name numbering to match dest1/2...
194 name
= "dest%d_o" % j
195 setattr(self
, name
, getattr(cu
, name
))
200 self
.rdmaskn
= cu
.rdmaskn
201 self
.wrmask
= cu
.wrmask
206 # HACK: get data width from dest[0]. this is used across the board
207 # (it really shouldn't be)
208 self
.data_wid
= self
.dest
[0].shape()
210 self
.go_rd_i
= self
.rd
.go_i
# temporary naming
211 self
.go_wr_i
= self
.wr
.go_i
# temporary naming
212 self
.go_ad_i
= self
.ad
.go_i
# temp naming: go address in
213 self
.go_st_i
= self
.st
.go_i
# temp naming: go store in
215 self
.rd_rel_o
= self
.rd
.rel_o
# temporary naming
216 self
.req_rel_o
= self
.wr
.rel_o
# temporary naming
217 self
.adr_rel_o
= self
.ad
.rel_o
# request address (from mem)
218 self
.sto_rel_o
= self
.st
.rel_o
# request store (to mem)
220 self
.issue_i
= cu
.issue_i
221 self
.shadown_i
= cu
.shadown_i
222 self
.go_die_i
= cu
.go_die_i
224 self
.oper_i
= cu
.oper_i
225 self
.src_i
= cu
._src
_i
227 self
.data_o
= Data(self
.data_wid
, name
="o") # Dest1 out: RT
228 self
.addr_o
= Data(self
.data_wid
, name
="ea") # Addr out: Update => RA
229 self
.addr_exc_o
= cu
.addr_exc_o
230 self
.done_o
= cu
.done_o
231 self
.busy_o
= cu
.busy_o
236 self
.load_mem_o
= cu
.load_mem_o
237 self
.stwd_mem_o
= cu
.stwd_mem_o
239 def elaborate(self
, platform
):
245 issue_i
= self
.issue_i
247 #####################
248 # latches for the FSM.
249 m
.submodules
.opc_l
= opc_l
= SRLatch(sync
=False, name
="opc")
250 m
.submodules
.src_l
= src_l
= SRLatch(False, self
.n_src
, name
="src")
251 m
.submodules
.alu_l
= alu_l
= SRLatch(sync
=False, name
="alu")
252 m
.submodules
.adr_l
= adr_l
= SRLatch(sync
=False, name
="adr")
253 m
.submodules
.lod_l
= lod_l
= SRLatch(sync
=False, name
="lod")
254 m
.submodules
.sto_l
= sto_l
= SRLatch(sync
=False, name
="sto")
255 m
.submodules
.wri_l
= wri_l
= SRLatch(sync
=False, name
="wri")
256 m
.submodules
.upd_l
= upd_l
= SRLatch(sync
=False, name
="upd")
257 m
.submodules
.rst_l
= rst_l
= SRLatch(sync
=False, name
="rst")
258 m
.submodules
.lsd_l
= lsd_l
= SRLatch(sync
=False, name
="lsd") # done
264 op_is_ld
= Signal(reset_less
=True)
265 op_is_st
= Signal(reset_less
=True)
267 # ALU/LD data output control
268 alu_valid
= Signal(reset_less
=True) # ALU operands are valid
269 alu_ok
= Signal(reset_less
=True) # ALU out ok (1 clock delay valid)
270 addr_ok
= Signal(reset_less
=True) # addr ok (from PortInterface)
271 ld_ok
= Signal(reset_less
=True) # LD out ok from PortInterface
272 wr_any
= Signal(reset_less
=True) # any write (incl. store)
273 rda_any
= Signal(reset_less
=True) # any read for address ops
274 rd_done
= Signal(reset_less
=True) # all *necessary* operands read
275 wr_reset
= Signal(reset_less
=True) # final reset condition
278 alu_o
= Signal(self
.data_wid
, reset_less
=True)
279 ldd_o
= Signal(self
.data_wid
, reset_less
=True)
281 ##############################
282 # reset conditions for latches
284 # temporaries (also convenient when debugging)
285 reset_o
= Signal(reset_less
=True) # reset opcode
286 reset_w
= Signal(reset_less
=True) # reset write
287 reset_u
= Signal(reset_less
=True) # reset update
288 reset_a
= Signal(reset_less
=True) # reset adr latch
289 reset_i
= Signal(reset_less
=True) # issue|die (use a lot)
290 reset_r
= Signal(self
.n_src
, reset_less
=True) # reset src
291 reset_s
= Signal(reset_less
=True) # reset store
293 comb
+= reset_i
.eq(issue_i | self
.go_die_i
) # various
294 comb
+= reset_o
.eq(wr_reset | self
.go_die_i
) # opcode reset
295 comb
+= reset_w
.eq(self
.wr
.go_i
[0] | self
.go_die_i
) # write reg 1
296 comb
+= reset_u
.eq(self
.wr
.go_i
[1] | self
.go_die_i
) # update (reg 2)
297 comb
+= reset_s
.eq(self
.go_st_i | self
.go_die_i
) # store reset
298 comb
+= reset_r
.eq(self
.rd
.go_i |
Repl(self
.go_die_i
, self
.n_src
))
299 comb
+= reset_a
.eq(self
.go_ad_i | self
.go_die_i
)
301 p_st_go
= Signal(reset_less
=True)
302 sync
+= p_st_go
.eq(self
.st
.go_i
)
304 ##########################
305 # FSM implemented through sequence of latches. approximately this:
307 # - src_l[0] : operands
309 # - alu_l : looks after add of src1/2/imm (EA)
310 # - adr_l : waits for add (EA)
311 # - upd_l : waits for adr and Regfile (port 2)
313 # - lod_l : waits for adr (EA) and for LD Data
314 # - wri_l : waits for LD Data and Regfile (port 1)
315 # - st_l : waits for alu and operand2
316 # - rst_l : waits for all FSM paths to converge.
317 # NOTE: use sync to stop combinatorial loops.
319 # opcode latch - inverted so that busy resets to 0
320 # note this MUST be sync so as to avoid a combinatorial loop
321 # between busy_o and issue_i on the reset latch (rst_l)
322 sync
+= opc_l
.s
.eq(issue_i
) # XXX NOTE: INVERTED FROM book!
323 sync
+= opc_l
.r
.eq(reset_o
) # XXX NOTE: INVERTED FROM book!
326 sync
+= src_l
.s
.eq(Repl(issue_i
, self
.n_src
))
327 sync
+= src_l
.r
.eq(reset_r
)
329 # alu latch. use sync-delay between alu_ok and valid to generate pulse
330 comb
+= alu_l
.s
.eq(reset_i
)
331 comb
+= alu_l
.r
.eq(alu_ok
& ~alu_valid
& ~rda_any
)
334 comb
+= adr_l
.s
.eq(reset_i
)
335 sync
+= adr_l
.r
.eq(reset_a
)
338 comb
+= lod_l
.s
.eq(reset_i
)
339 comb
+= lod_l
.r
.eq(ld_ok
)
342 comb
+= wri_l
.s
.eq(issue_i
)
343 sync
+= wri_l
.r
.eq(reset_w |
Repl(self
.done_o
, self
.n_dst
))
345 # update-mode operand latch (EA written to reg 2)
346 sync
+= upd_l
.s
.eq(reset_i
)
347 sync
+= upd_l
.r
.eq(reset_u
)
350 comb
+= sto_l
.s
.eq(addr_ok
& op_is_st
)
351 sync
+= sto_l
.r
.eq(reset_s | p_st_go
)
353 # ld/st done. needed to stop LD/ST from activating repeatedly
354 comb
+= lsd_l
.s
.eq(issue_i
)
355 sync
+= lsd_l
.r
.eq(reset_s | p_st_go | ld_ok
)
358 comb
+= rst_l
.s
.eq(addr_ok
) # start when address is ready
359 comb
+= rst_l
.r
.eq(issue_i
)
361 # create a latch/register for the operand
362 oper_r
= CompLDSTOpSubset(name
="oper_r") # Dest register
363 with m
.If(self
.issue_i
):
364 sync
+= oper_r
.eq(self
.oper_i
)
365 with m
.If(self
.done_o
):
369 ldd_r
= Signal(self
.data_wid
, reset_less
=True) # Dest register
370 latchregister(m
, ldd_o
, ldd_r
, ld_ok
, name
="ldo_r")
372 # and for each input from the incoming src operands
374 for i
in range(self
.n_src
):
376 src_r
= Signal(self
.data_wid
, name
=name
, reset_less
=True)
377 with m
.If(self
.rd
.go_i
[i
]):
378 sync
+= src_r
.eq(self
.src_i
[i
])
379 with m
.If(self
.issue_i
):
383 # and one for the output from the ADD (for the EA)
384 addr_r
= Signal(self
.data_wid
, reset_less
=True) # Effective Address
385 latchregister(m
, alu_o
, addr_r
, alu_l
.q
, "ea_r")
387 # select either zero or src1 if opcode says so
388 op_is_z
= oper_r
.zero_a
389 src1_or_z
= Signal(self
.data_wid
, reset_less
=True)
390 m
.d
.comb
+= src1_or_z
.eq(Mux(op_is_z
, 0, srl
[0]))
392 # select either immediate or src2 if opcode says so
393 op_is_imm
= oper_r
.imm_data
.imm_ok
394 src2_or_imm
= Signal(self
.data_wid
, reset_less
=True)
395 m
.d
.comb
+= src2_or_imm
.eq(Mux(op_is_imm
, oper_r
.imm_data
.imm
, srl
[1]))
397 # now do the ALU addr add: one cycle, and say "ready" (next cycle, too)
398 comb
+= alu_o
.eq(src1_or_z
+ src2_or_imm
) # actual EA
399 m
.d
.sync
+= alu_ok
.eq(alu_valid
) # keep ack in sync with EA
401 # decode bits of operand (latched)
402 comb
+= op_is_st
.eq(oper_r
.insn_type
== MicrOp
.OP_STORE
) # ST
403 comb
+= op_is_ld
.eq(oper_r
.insn_type
== MicrOp
.OP_LOAD
) # LD
404 op_is_update
= oper_r
.ldst_mode
== LDSTMode
.update
# UPDATE
405 op_is_cix
= oper_r
.ldst_mode
== LDSTMode
.cix
# cache-inhibit
406 comb
+= self
.load_mem_o
.eq(op_is_ld
& self
.go_ad_i
)
407 comb
+= self
.stwd_mem_o
.eq(op_is_st
& self
.go_st_i
)
408 comb
+= self
.ld_o
.eq(op_is_ld
)
409 comb
+= self
.st_o
.eq(op_is_st
)
411 ############################
412 # Control Signal calculation
416 comb
+= self
.busy_o
.eq(opc_l
.q
) # | self.pi.busy_o) # busy out
418 # 1st operand read-request only when zero not active
419 # 2nd operand only needed when immediate is not active
420 slg
= Cat(op_is_z
, op_is_imm
)
421 bro
= Repl(self
.busy_o
, self
.n_src
)
422 comb
+= self
.rd
.rel_o
.eq(src_l
.q
& bro
& ~slg
& ~self
.rdmaskn
)
424 # note when the address-related read "go" signals are active
425 comb
+= rda_any
.eq(self
.rd
.go_i
[0] | self
.rd
.go_i
[1])
427 # alu input valid when 1st and 2nd ops done (or imm not active)
428 comb
+= alu_valid
.eq(busy_o
& ~
(self
.rd
.rel_o
[0] | self
.rd
.rel_o
[1]))
430 # 3rd operand only needed when operation is a store
431 comb
+= self
.rd
.rel_o
[2].eq(src_l
.q
[2] & busy_o
& op_is_st
)
433 # all reads done when alu is valid and 3rd operand needed
434 comb
+= rd_done
.eq(alu_valid
& ~self
.rd
.rel_o
[2])
436 # address release only if addr ready, but Port must be idle
437 comb
+= self
.adr_rel_o
.eq(alu_valid
& adr_l
.q
& busy_o
)
439 # store release when st ready *and* all operands read (and no shadow)
440 comb
+= self
.st
.rel_o
.eq(sto_l
.q
& busy_o
& rd_done
& op_is_st
&
443 # request write of LD result. waits until shadow is dropped.
444 comb
+= self
.wr
.rel_o
[0].eq(rd_done
& wri_l
.q
& busy_o
& lod_l
.qn
&
445 op_is_ld
& self
.shadown_i
)
447 # request write of EA result only in update mode
448 comb
+= self
.wr
.rel_o
[1].eq(upd_l
.q
& busy_o
& op_is_update
&
449 alu_valid
& self
.shadown_i
)
451 # provide "done" signal: select req_rel for non-LD/ST, adr_rel for LD/ST
452 comb
+= wr_any
.eq(self
.st
.go_i | p_st_go |
453 self
.wr
.go_i
[0] | self
.wr
.go_i
[1])
454 comb
+= wr_reset
.eq(rst_l
.q
& busy_o
& self
.shadown_i
&
455 ~
(self
.st
.rel_o | self
.wr
.rel_o
[0] |
457 (lod_l
.qn | op_is_st
) &
458 (~self
.pi
.busy_o | op_is_ld
))
459 comb
+= self
.done_o
.eq(wr_reset
)
461 ######################
462 # Data/Address outputs
464 # put the LD-output register directly onto the output bus on a go_write
465 comb
+= self
.data_o
.data
.eq(self
.dest
[0])
466 with m
.If(self
.wr
.go_i
[0]):
467 comb
+= self
.dest
[0].eq(ldd_r
)
469 # "update" mode, put address out on 2nd go-write
470 comb
+= self
.addr_o
.data
.eq(self
.dest
[1])
471 with m
.If(op_is_update
& self
.wr
.go_i
[1]):
472 comb
+= self
.dest
[1].eq(addr_r
)
474 # need to look like MultiCompUnit: put wrmask out.
475 # XXX may need to make this enable only when write active
476 comb
+= self
.wrmask
.eq(bro
& Cat(op_is_ld
, op_is_update
))
478 ###########################
479 # PortInterface connections
482 # connect to LD/ST PortInterface.
483 comb
+= pi
.is_ld_i
.eq(op_is_ld
& busy_o
) # decoded-LD
484 comb
+= pi
.is_st_i
.eq(op_is_st
& busy_o
) # decoded-ST
485 comb
+= pi
.data_len
.eq(oper_r
.data_len
) # data_len
486 # address: use sync to avoid long latency
487 sync
+= pi
.addr
.data
.eq(addr_r
) # EA from adder
488 sync
+= pi
.addr
.ok
.eq(alu_ok
& lsd_l
.q
) # "do address stuff" (once)
489 comb
+= self
.addr_exc_o
.eq(pi
.addr_exc_o
) # exception occurred
490 comb
+= addr_ok
.eq(self
.pi
.addr_ok_o
) # no exc, address fine
493 with m
.If(oper_r
.byte_reverse
):
494 # byte-reverse the data based on ld/st width (turn it to LE)
495 data_len
= oper_r
.data_len
496 lddata_r
= byte_reverse(m
, 'lddata_r', pi
.ld
.data
, data_len
)
497 comb
+= ldd_o
.eq(lddata_r
) # put reversed- data out
499 comb
+= ldd_o
.eq(pi
.ld
.data
) # put data out, straight (as BE)
500 # ld - ld gets latched in via lod_l
501 comb
+= ld_ok
.eq(pi
.ld
.ok
) # ld.ok *closes* (freezes) ld data
504 op3
= srl
[2] # 3rd operand latch
505 with m
.If(oper_r
.byte_reverse
):
506 # byte-reverse the data based on width
507 data_len
= oper_r
.data_len
508 stdata_r
= byte_reverse(m
, 'stdata_r', op3
, data_len
)
509 comb
+= pi
.st
.data
.eq(stdata_r
)
511 comb
+= pi
.st
.data
.eq(op3
)
512 # store - data goes in based on go_st
513 comb
+= pi
.st
.ok
.eq(self
.st
.go_i
) # go store signals st data valid
517 def get_out(self
, i
):
518 """make LDSTCompUnit look like RegSpecALUAPI"""
523 # return self.dest[i]
525 def get_fu_out(self
, i
):
526 return self
.get_out(i
)
536 yield from self
.oper_i
.ports()
537 yield from self
.src_i
543 yield from self
.data_o
.ports()
544 yield from self
.addr_o
.ports()
545 yield self
.load_mem_o
546 yield self
.stwd_mem_o
552 def wait_for(sig
, wait
=True, test1st
=False):
554 print("wait for", sig
, v
, wait
, test1st
)
555 if test1st
and bool(v
) == wait
:
560 #print("...wait for", sig, v)
565 def store(dut
, src1
, src2
, src3
, imm
, imm_ok
=True, update
=False,
567 print("ST", src1
, src2
, src3
, imm
, imm_ok
, update
)
568 yield dut
.oper_i
.insn_type
.eq(MicrOp
.OP_STORE
)
569 yield dut
.oper_i
.data_len
.eq(2) # half-word
570 yield dut
.oper_i
.byte_reverse
.eq(byterev
)
571 yield dut
.src1_i
.eq(src1
)
572 yield dut
.src2_i
.eq(src2
)
573 yield dut
.src3_i
.eq(src3
)
574 yield dut
.oper_i
.imm_data
.imm
.eq(imm
)
575 yield dut
.oper_i
.imm_data
.imm_ok
.eq(imm_ok
)
576 yield dut
.oper_i
.update
.eq(update
)
577 yield dut
.issue_i
.eq(1)
579 yield dut
.issue_i
.eq(0)
585 # wait for all active rel signals to come up
587 rel
= yield dut
.rd
.rel_o
588 if rel
== active_rel
:
591 yield dut
.rd
.go
.eq(active_rel
)
593 yield dut
.rd
.go
.eq(0)
595 yield from wait_for(dut
.adr_rel_o
, False, test1st
=True)
596 # yield from wait_for(dut.adr_rel_o)
597 # yield dut.ad.go.eq(1)
599 # yield dut.ad.go.eq(0)
602 yield from wait_for(dut
.wr
.rel_o
[1])
603 yield dut
.wr
.go
.eq(0b10)
605 addr
= yield dut
.addr_o
607 yield dut
.wr
.go
.eq(0)
611 yield from wait_for(dut
.sto_rel_o
)
612 yield dut
.go_st_i
.eq(1)
614 yield dut
.go_st_i
.eq(0)
615 yield from wait_for(dut
.busy_o
, False)
616 # wait_for(dut.stwd_mem_o)
621 def load(dut
, src1
, src2
, imm
, imm_ok
=True, update
=False, zero_a
=False,
623 print("LD", src1
, src2
, imm
, imm_ok
, update
)
624 yield dut
.oper_i
.insn_type
.eq(MicrOp
.OP_LOAD
)
625 yield dut
.oper_i
.data_len
.eq(2) # half-word
626 yield dut
.oper_i
.byte_reverse
.eq(byterev
)
627 yield dut
.src1_i
.eq(src1
)
628 yield dut
.src2_i
.eq(src2
)
629 yield dut
.oper_i
.zero_a
.eq(zero_a
)
630 yield dut
.oper_i
.imm_data
.imm
.eq(imm
)
631 yield dut
.oper_i
.imm_data
.imm_ok
.eq(imm_ok
)
632 yield dut
.issue_i
.eq(1)
634 yield dut
.issue_i
.eq(0)
637 # set up read-operand flags
639 if not imm_ok
: # no immediate means RB register needs to be read
641 if not zero_a
: # no zero-a means RA needs to be read
644 # wait for the operands (RA, RB, or both)
646 yield dut
.rd
.go
.eq(rd
)
647 yield from wait_for(dut
.rd
.rel_o
)
648 yield dut
.rd
.go
.eq(0)
650 yield from wait_for(dut
.adr_rel_o
, False, test1st
=True)
651 # yield dut.ad.go.eq(1)
653 # yield dut.ad.go.eq(0)
656 yield from wait_for(dut
.wr
.rel_o
[1])
657 yield dut
.wr
.go
.eq(0b10)
659 addr
= yield dut
.addr_o
661 yield dut
.wr
.go
.eq(0)
665 yield from wait_for(dut
.wr
.rel_o
[0], test1st
=True)
666 yield dut
.wr
.go
.eq(1)
668 data
= yield dut
.data_o
670 yield dut
.wr
.go
.eq(0)
671 yield from wait_for(dut
.busy_o
)
673 # wait_for(dut.stwd_mem_o)
682 # two STs (different addresses)
683 yield from store(dut
, 4, 0, 3, 2) # ST reg4 into addr rfile[reg3]+2
684 yield from store(dut
, 2, 0, 9, 2) # ST reg4 into addr rfile[reg9]+2
686 # two LDs (deliberately LD from the 1st address then 2nd)
687 data
, addr
= yield from load(dut
, 4, 0, 2)
688 assert data
== 0x0003, "returned %x" % data
689 data
, addr
= yield from load(dut
, 2, 0, 2)
690 assert data
== 0x0009, "returned %x" % data
694 yield from store(dut
, 9, 5, 3, 0, imm_ok
=False)
695 data
, addr
= yield from load(dut
, 9, 5, 0, imm_ok
=False)
696 assert data
== 0x0003, "returned %x" % data
698 # update-immediate version
699 addr
= yield from store(dut
, 9, 6, 3, 2, update
=True)
700 assert addr
== 0x000b, "returned %x" % addr
702 # update-indexed version
703 data
, addr
= yield from load(dut
, 9, 5, 0, imm_ok
=False, update
=True)
704 assert data
== 0x0003, "returned %x" % data
705 assert addr
== 0x000e, "returned %x" % addr
707 # immediate *and* zero version
708 data
, addr
= yield from load(dut
, 1, 4, 8, imm_ok
=True, zero_a
=True)
709 assert data
== 0x0008, "returned %x" % data
712 class TestLDSTCompUnit(LDSTCompUnit
):
714 def __init__(self
, rwid
):
715 from soc
.experiment
.l0_cache
import TstL0CacheBuffer
716 self
.l0
= l0
= TstL0CacheBuffer()
717 pi
= l0
.l0
.dports
[0].pi
718 LDSTCompUnit
.__init
__(self
, pi
, rwid
, 4)
720 def elaborate(self
, platform
):
721 m
= LDSTCompUnit
.elaborate(self
, platform
)
722 m
.submodules
.l0
= self
.l0
723 m
.d
.comb
+= self
.ad
.go
.eq(self
.ad
.rel
) # link addr-go direct to rel
727 def test_scoreboard():
729 dut
= TestLDSTCompUnit(16)
730 vl
= rtlil
.convert(dut
, ports
=dut
.ports())
731 with
open("test_ldst_comp.il", "w") as f
:
734 run_simulation(dut
, ldst_sim(dut
), vcd_name
='test_ldst_comp.vcd')
737 class TestLDSTCompUnitRegSpec(LDSTCompUnit
):
740 from soc
.experiment
.l0_cache
import TstL0CacheBuffer
741 from soc
.fu
.ldst
.pipe_data
import LDSTPipeSpec
742 regspec
= LDSTPipeSpec
.regspec
743 self
.l0
= l0
= TstL0CacheBuffer()
744 pi
= l0
.l0
.dports
[0].pi
745 LDSTCompUnit
.__init
__(self
, pi
, regspec
, 4)
747 def elaborate(self
, platform
):
748 m
= LDSTCompUnit
.elaborate(self
, platform
)
749 m
.submodules
.l0
= self
.l0
750 m
.d
.comb
+= self
.ad
.go
.eq(self
.ad
.rel
) # link addr-go direct to rel
754 def test_scoreboard_regspec():
756 dut
= TestLDSTCompUnitRegSpec()
757 vl
= rtlil
.convert(dut
, ports
=dut
.ports())
758 with
open("test_ldst_comp.il", "w") as f
:
761 run_simulation(dut
, ldst_sim(dut
), vcd_name
='test_ldst_regspec.vcd')
764 if __name__
== '__main__':
765 test_scoreboard_regspec()