3 based on Anton Blanchard microwatt icache.vhdl
7 TODO (in no specific order):
8 * Add debug interface to inspect cache content
9 * Add snoop/invalidate path
10 * Add multi-hit error detection
11 * Pipelined bus interface (wb or axi)
12 * Maybe add parity? There's a few bits free in each BRAM row on Xilinx
13 * Add optimization: service hits on partially loaded lines
14 * Add optimization: (maybe) interrupt reload on fluch/redirect
15 * Check if playing with the geometry of the cache tags allow for more
16 efficient use of distributed RAM and less logic/muxes. Currently we
17 write TAG_BITS width which may not match full ram blocks and might
18 cause muxes to be inferred for "partial writes".
19 * Check if making the read size of PLRU a ROM helps utilization
22 from enum
import Enum
, unique
23 from nmigen
import (Module
, Signal
, Elaboratable
, Cat
, Array
, Const
, Repl
)
24 from nmigen
.cli
import main
, rtlil
25 from nmutil
.iocontrol
import RecordObject
26 from nmigen
.utils
import log2_int
27 from nmutil
.util
import Display
29 #from nmutil.plru import PLRU
30 from soc
.experiment
.cache_ram
import CacheRam
31 from soc
.experiment
.plru
import PLRU
33 from soc
.experiment
.mem_types
import (Fetch1ToICacheType
,
37 from soc
.experiment
.wb_types
import (WB_ADDR_BITS
, WB_DATA_BITS
,
38 WB_SEL_BITS
, WBAddrType
, WBDataType
,
39 WBSelType
, WBMasterOut
, WBSlaveOut
,
40 WBMasterOutVector
, WBSlaveOutVector
,
41 WBIOMasterOut
, WBIOSlaveOut
)
44 from nmigen_soc
.wishbone
.sram
import SRAM
45 from nmigen
import Memory
46 from nmutil
.util
import wrap
47 from nmigen
.cli
import main
, rtlil
49 from nmigen
.back
.pysim
import Simulator
, Delay
, Settle
51 from nmigen
.sim
.cxxsim
import Simulator
, Delay
, Settle
56 # BRAM organisation: We never access more than wishbone_data_bits
57 # at a time so to save resources we make the array only that wide,
58 # and use consecutive indices for to make a cache "line"
60 # ROW_SIZE is the width in bytes of the BRAM (based on WB, so 64-bits)
61 ROW_SIZE
= WB_DATA_BITS
// 8
62 # Number of lines in a set
66 # L1 ITLB number of entries (direct mapped)
68 # L1 ITLB log_2(page_size)
70 # Number of real address bits that we store
72 # Non-zero to enable log data collection
75 ROW_SIZE_BITS
= ROW_SIZE
* 8
76 # ROW_PER_LINE is the number of row
77 # (wishbone) transactions in a line
78 ROW_PER_LINE
= LINE_SIZE
// ROW_SIZE
79 # BRAM_ROWS is the number of rows in
80 # BRAM needed to represent the full icache
81 BRAM_ROWS
= NUM_LINES
* ROW_PER_LINE
82 # INSN_PER_ROW is the number of 32bit
83 # instructions per BRAM row
84 INSN_PER_ROW
= ROW_SIZE_BITS
// 32
86 print("ROW_SIZE", ROW_SIZE
)
87 print("ROW_SIZE_BITS", ROW_SIZE_BITS
)
88 print("ROW_PER_LINE", ROW_PER_LINE
)
89 print("BRAM_ROWS", BRAM_ROWS
)
90 print("INSN_PER_ROW", INSN_PER_ROW
)
92 # Bit fields counts in the address
94 # INSN_BITS is the number of bits to
95 # select an instruction in a row
96 INSN_BITS
= log2_int(INSN_PER_ROW
)
97 # ROW_BITS is the number of bits to
99 ROW_BITS
= log2_int(BRAM_ROWS
)
100 # ROW_LINEBITS is the number of bits to
101 # select a row within a line
102 ROW_LINEBITS
= log2_int(ROW_PER_LINE
)
103 # LINE_OFF_BITS is the number of bits for
104 # the offset in a cache line
105 LINE_OFF_BITS
= log2_int(LINE_SIZE
)
106 # ROW_OFF_BITS is the number of bits for
107 # the offset in a row
108 ROW_OFF_BITS
= log2_int(ROW_SIZE
)
109 # INDEX_BITS is the number of bits to
110 # select a cache line
111 INDEX_BITS
= log2_int(NUM_LINES
)
112 # SET_SIZE_BITS is the log base 2 of
114 SET_SIZE_BITS
= LINE_OFF_BITS
+ INDEX_BITS
115 # TAG_BITS is the number of bits of
116 # the tag part of the address
117 TAG_BITS
= REAL_ADDR_BITS
- SET_SIZE_BITS
118 # TAG_WIDTH is the width in bits of each way of the tag RAM
119 TAG_WIDTH
= TAG_BITS
+ 7 - ((TAG_BITS
+ 7) % 8)
121 # WAY_BITS is the number of bits to
123 WAY_BITS
= log2_int(NUM_WAYS
)
124 TAG_RAM_WIDTH
= TAG_BITS
* NUM_WAYS
127 # constant TLB_BITS : natural := log2(TLB_SIZE);
128 # constant TLB_EA_TAG_BITS : natural := 64 - (TLB_LG_PGSZ + TLB_BITS);
129 # constant TLB_PTE_BITS : natural := 64;
130 TLB_BITS
= log2_int(TLB_SIZE
)
131 TLB_EA_TAG_BITS
= 64 - (TLB_LG_PGSZ
+ TLB_BITS
)
135 print("INSN_BITS", INSN_BITS
)
136 print("ROW_BITS", ROW_BITS
)
137 print("ROW_LINEBITS", ROW_LINEBITS
)
138 print("LINE_OFF_BITS", LINE_OFF_BITS
)
139 print("ROW_OFF_BITS", ROW_OFF_BITS
)
140 print("INDEX_BITS", INDEX_BITS
)
141 print("SET_SIZE_BITS", SET_SIZE_BITS
)
142 print("TAG_BITS", TAG_BITS
)
143 print("WAY_BITS", WAY_BITS
)
144 print("TAG_RAM_WIDTH", TAG_RAM_WIDTH
)
145 print("TLB_BITS", TLB_BITS
)
146 print("TLB_EA_TAG_BITS", TLB_EA_TAG_BITS
)
147 print("TLB_PTE_BITS", TLB_PTE_BITS
)
152 # architecture rtl of icache is
153 #constant ROW_SIZE_BITS : natural := ROW_SIZE*8;
154 #-- ROW_PER_LINE is the number of row (wishbone
155 #-- transactions) in a line
156 #constant ROW_PER_LINE : natural := LINE_SIZE / ROW_SIZE;
157 #-- BRAM_ROWS is the number of rows in BRAM
158 #-- needed to represent the full
160 #constant BRAM_ROWS : natural := NUM_LINES * ROW_PER_LINE;
161 #-- INSN_PER_ROW is the number of 32bit instructions per BRAM row
162 #constant INSN_PER_ROW : natural := ROW_SIZE_BITS / 32;
163 #-- Bit fields counts in the address
165 #-- INSN_BITS is the number of bits to select
166 #-- an instruction in a row
167 #constant INSN_BITS : natural := log2(INSN_PER_ROW);
168 #-- ROW_BITS is the number of bits to select a row
169 #constant ROW_BITS : natural := log2(BRAM_ROWS);
170 #-- ROW_LINEBITS is the number of bits to
171 #-- select a row within a line
172 #constant ROW_LINEBITS : natural := log2(ROW_PER_LINE);
173 #-- LINE_OFF_BITS is the number of bits for the offset
175 #constant LINE_OFF_BITS : natural := log2(LINE_SIZE);
176 #-- ROW_OFF_BITS is the number of bits for the offset in a row
177 #constant ROW_OFF_BITS : natural := log2(ROW_SIZE);
178 #-- INDEX_BITS is the number of bits to select a cache line
179 #constant INDEX_BITS : natural := log2(NUM_LINES);
180 #-- SET_SIZE_BITS is the log base 2 of the set size
181 #constant SET_SIZE_BITS : natural := LINE_OFF_BITS + INDEX_BITS;
182 #-- TAG_BITS is the number of bits of the tag part of the address
183 #constant TAG_BITS : natural := REAL_ADDR_BITS - SET_SIZE_BITS;
184 #-- WAY_BITS is the number of bits to select a way
185 #constant WAY_BITS : natural := log2(NUM_WAYS);
187 #-- Example of layout for 32 lines of 64 bytes:
189 #-- .. tag |index| line |
191 #-- .. | | | |00| zero (2)
192 #-- .. | | |-| | INSN_BITS (1)
193 #-- .. | |---| | ROW_LINEBITS (3)
194 #-- .. | |--- - --| LINE_OFF_BITS (6)
195 #-- .. | |- --| ROW_OFF_BITS (3)
196 #-- .. |----- ---| | ROW_BITS (8)
197 #-- .. |-----| | INDEX_BITS (5)
198 #-- .. --------| | TAG_BITS (53)
199 # Example of layout for 32 lines of 64 bytes:
201 # .. tag |index| line |
203 # .. | | | |00| zero (2)
204 # .. | | |-| | INSN_BITS (1)
205 # .. | |---| | ROW_LINEBITS (3)
206 # .. | |--- - --| LINE_OFF_BITS (6)
207 # .. | |- --| ROW_OFF_BITS (3)
208 # .. |----- ---| | ROW_BITS (8)
209 # .. |-----| | INDEX_BITS (5)
210 # .. --------| | TAG_BITS (53)
212 #subtype row_t is integer range 0 to BRAM_ROWS-1;
213 #subtype index_t is integer range 0 to NUM_LINES-1;
214 #subtype way_t is integer range 0 to NUM_WAYS-1;
215 #subtype row_in_line_t is unsigned(ROW_LINEBITS-1 downto 0);
217 #-- The cache data BRAM organized as described above for each way
218 #subtype cache_row_t is std_ulogic_vector(ROW_SIZE_BITS-1 downto 0);
220 #-- The cache tags LUTRAM has a row per set. Vivado is a pain and will
221 #-- not handle a clean (commented) definition of the cache tags as a 3d
222 #-- memory. For now, work around it by putting all the tags
223 #subtype cache_tag_t is std_logic_vector(TAG_BITS-1 downto 0);
224 # type cache_tags_set_t is array(way_t) of cache_tag_t;
225 # type cache_tags_array_t is array(index_t) of cache_tags_set_t;
226 #constant TAG_RAM_WIDTH : natural := TAG_BITS * NUM_WAYS;
227 #subtype cache_tags_set_t is std_logic_vector(TAG_RAM_WIDTH-1 downto 0);
228 #type cache_tags_array_t is array(index_t) of cache_tags_set_t;
230 return Array(Signal(TAG_RAM_WIDTH
, name
="cachetag_%d" %x) \
231 for x
in range(NUM_LINES
))
233 #-- The cache valid bits
234 #subtype cache_way_valids_t is std_ulogic_vector(NUM_WAYS-1 downto 0);
235 #type cache_valids_t is array(index_t) of cache_way_valids_t;
236 #type row_per_line_valid_t is array(0 to ROW_PER_LINE - 1) of std_ulogic;
237 def CacheValidBitsArray():
238 return Array(Signal(NUM_WAYS
, name
="cachevalid_%d" %x) \
239 for x
in range(NUM_LINES
))
241 def RowPerLineValidArray():
242 return Array(Signal(name
="rows_valid_%d" %x) \
243 for x
in range(ROW_PER_LINE
))
246 #attribute ram_style : string;
247 #attribute ram_style of cache_tags : signal is "distributed";
248 # TODO to be passed to nigmen as ram attributes
249 # attribute ram_style : string;
250 # attribute ram_style of cache_tags : signal is "distributed";
253 #subtype tlb_index_t is integer range 0 to TLB_SIZE - 1;
254 #type tlb_valids_t is array(tlb_index_t) of std_ulogic;
255 #subtype tlb_tag_t is std_ulogic_vector(TLB_EA_TAG_BITS - 1 downto 0);
256 #type tlb_tags_t is array(tlb_index_t) of tlb_tag_t;
257 #subtype tlb_pte_t is std_ulogic_vector(TLB_PTE_BITS - 1 downto 0);
258 #type tlb_ptes_t is array(tlb_index_t) of tlb_pte_t;
259 def TLBValidBitsArray():
260 return Array(Signal(name
="tlbvalid_%d" %x) \
261 for x
in range(TLB_SIZE
))
264 return Array(Signal(TLB_EA_TAG_BITS
, name
="tlbtag_%d" %x) \
265 for x
in range(TLB_SIZE
))
268 return Array(Signal(TLB_PTE_BITS
, name
="tlbptes_%d" %x) \
269 for x
in range(TLB_SIZE
))
272 #-- Cache RAM interface
273 #type cache_ram_out_t is array(way_t) of cache_row_t;
274 # Cache RAM interface
276 return Array(Signal(ROW_SIZE_BITS
, name
="cache_out_%d" %x) \
277 for x
in range(NUM_WAYS
))
279 #-- PLRU output interface
280 #type plru_out_t is array(index_t) of
281 # std_ulogic_vector(WAY_BITS-1 downto 0);
282 # PLRU output interface
284 return Array(Signal(WAY_BITS
, name
="plru_out_%d" %x) \
285 for x
in range(NUM_LINES
))
287 # -- Return the cache line index (tag index) for an address
288 # function get_index(addr: std_ulogic_vector(63 downto 0))
291 # return to_integer(unsigned(
292 # addr(SET_SIZE_BITS - 1 downto LINE_OFF_BITS)
295 # Return the cache line index (tag index) for an address
297 return addr
[LINE_OFF_BITS
:SET_SIZE_BITS
]
299 # -- Return the cache row index (data memory) for an address
300 # function get_row(addr: std_ulogic_vector(63 downto 0))
303 # return to_integer(unsigned(
304 # addr(SET_SIZE_BITS - 1 downto ROW_OFF_BITS)
307 # Return the cache row index (data memory) for an address
309 return addr
[ROW_OFF_BITS
:SET_SIZE_BITS
]
311 # -- Return the index of a row within a line
312 # function get_row_of_line(row: row_t) return row_in_line_t is
313 # variable row_v : unsigned(ROW_BITS-1 downto 0);
315 # row_v := to_unsigned(row, ROW_BITS);
316 # return row_v(ROW_LINEBITS-1 downto 0);
318 # Return the index of a row within a line
319 def get_row_of_line(row
):
320 return row
[:ROW_LINEBITS
]
322 # -- Returns whether this is the last row of a line
323 # function is_last_row_addr(addr: wishbone_addr_type;
324 # last: row_in_line_t
329 # addr(LINE_OFF_BITS-1 downto ROW_OFF_BITS)
332 # Returns whether this is the last row of a line
333 def is_last_row_addr(addr
, last
):
334 return addr
[ROW_OFF_BITS
:LINE_OFF_BITS
] == last
336 # -- Returns whether this is the last row of a line
337 # function is_last_row(row: row_t;
338 # last: row_in_line_t) return boolean is
340 # return get_row_of_line(row) = last;
342 # Returns whether this is the last row of a line
343 def is_last_row(row
, last
):
344 return get_row_of_line(row
) == last
346 # -- Return the next row in the current cache line. We use a dedicated
347 # -- function in order to limit the size of the generated adder to be
348 # -- only the bits within a cache line (3 bits with default settings)
349 # function next_row(row: row_t) return row_t is
350 # variable row_v : std_ulogic_vector(ROW_BITS-1 downto 0);
351 # variable row_idx : std_ulogic_vector(ROW_LINEBITS-1 downto 0);
352 # variable result : std_ulogic_vector(ROW_BITS-1 downto 0);
354 # row_v := std_ulogic_vector(to_unsigned(row, ROW_BITS));
355 # row_idx := row_v(ROW_LINEBITS-1 downto 0);
356 # row_v(ROW_LINEBITS-1 downto 0) :=
357 # std_ulogic_vector(unsigned(row_idx) + 1);
358 # return to_integer(unsigned(row_v));
360 # Return the next row in the current cache line. We use a dedicated
361 # function in order to limit the size of the generated adder to be
362 # only the bits within a cache line (3 bits with default settings)
364 row_v
= row
[0:ROW_LINEBITS
] + 1
365 return Cat(row_v
[:ROW_LINEBITS
], row
[ROW_LINEBITS
:])
366 # -- Read the instruction word for the given address in the
367 # -- current cache row
368 # function read_insn_word(addr: std_ulogic_vector(63 downto 0);
369 # data: cache_row_t) return std_ulogic_vector is
370 # variable word: integer range 0 to INSN_PER_ROW-1;
372 # word := to_integer(unsigned(addr(INSN_BITS+2-1 downto 2)));
373 # return data(31+word*32 downto word*32);
375 # Read the instruction word for the given address
376 # in the current cache row
377 def read_insn_word(addr
, data
):
378 word
= addr
[2:INSN_BITS
+2]
379 return data
.word_select(word
, 32)
381 # -- Get the tag value from the address
383 # addr: std_ulogic_vector(REAL_ADDR_BITS - 1 downto 0)
385 # return cache_tag_t is
387 # return addr(REAL_ADDR_BITS - 1 downto SET_SIZE_BITS);
389 # Get the tag value from the address
391 return addr
[SET_SIZE_BITS
:REAL_ADDR_BITS
]
393 # -- Read a tag from a tag memory row
394 # function read_tag(way: way_t; tagset: cache_tags_set_t)
395 # return cache_tag_t is
397 # return tagset((way+1) * TAG_BITS - 1 downto way * TAG_BITS);
399 # Read a tag from a tag memory row
400 def read_tag(way
, tagset
):
401 return tagset
.word_select(way
, TAG_BITS
)
403 # -- Write a tag to tag memory row
404 # procedure write_tag(way: in way_t;
405 # tagset: inout cache_tags_set_t; tag: cache_tag_t) is
407 # tagset((way+1) * TAG_BITS - 1 downto way * TAG_BITS) := tag;
409 # Write a tag to tag memory row
410 def write_tag(way
, tagset
, tag
):
411 return read_tag(way
, tagset
).eq(tag
)
413 # -- Simple hash for direct-mapped TLB index
414 # function hash_ea(addr: std_ulogic_vector(63 downto 0))
415 # return tlb_index_t is
416 # variable hash : std_ulogic_vector(TLB_BITS - 1 downto 0);
418 # hash := addr(TLB_LG_PGSZ + TLB_BITS - 1 downto TLB_LG_PGSZ)
420 # TLB_LG_PGSZ + 2 * TLB_BITS - 1 downto
421 # TLB_LG_PGSZ + TLB_BITS
424 # TLB_LG_PGSZ + 3 * TLB_BITS - 1 downto
425 # TLB_LG_PGSZ + 2 * TLB_BITS
427 # return to_integer(unsigned(hash));
429 # Simple hash for direct-mapped TLB index
431 hsh
= addr
[TLB_LG_PGSZ
:TLB_LG_PGSZ
+ TLB_BITS
] ^ addr
[
432 TLB_LG_PGSZ
+ TLB_BITS
:TLB_LG_PGSZ
+ 2 * TLB_BITS
434 TLB_LG_PGSZ
+ 2 * TLB_BITS
:TLB_LG_PGSZ
+ 3 * TLB_BITS
440 # XXX put these assert statements in - as python asserts
442 # assert LINE_SIZE mod ROW_SIZE = 0;
443 # assert ispow2(LINE_SIZE) report "LINE_SIZE not power of 2"
444 # assert ispow2(NUM_LINES) report "NUM_LINES not power of 2"
445 # assert ispow2(ROW_PER_LINE) report "ROW_PER_LINE not power of 2"
446 # assert ispow2(INSN_PER_ROW) report "INSN_PER_ROW not power of 2"
447 # assert (ROW_BITS = INDEX_BITS + ROW_LINEBITS)
448 # report "geometry bits don't add up"
449 # assert (LINE_OFF_BITS = ROW_OFF_BITS + ROW_LINEBITS)
450 # report "geometry bits don't add up"
451 # assert (REAL_ADDR_BITS = TAG_BITS + INDEX_BITS + LINE_OFF_BITS)
452 # report "geometry bits don't add up"
453 # assert (REAL_ADDR_BITS = TAG_BITS + ROW_BITS + ROW_OFF_BITS)
454 # report "geometry bits don't add up"
456 # sim_debug: if SIM generate
459 # report "ROW_SIZE = " & natural'image(ROW_SIZE);
460 # report "ROW_PER_LINE = " & natural'image(ROW_PER_LINE);
461 # report "BRAM_ROWS = " & natural'image(BRAM_ROWS);
462 # report "INSN_PER_ROW = " & natural'image(INSN_PER_ROW);
463 # report "INSN_BITS = " & natural'image(INSN_BITS);
464 # report "ROW_BITS = " & natural'image(ROW_BITS);
465 # report "ROW_LINEBITS = " & natural'image(ROW_LINEBITS);
466 # report "LINE_OFF_BITS = " & natural'image(LINE_OFF_BITS);
467 # report "ROW_OFF_BITS = " & natural'image(ROW_OFF_BITS);
468 # report "INDEX_BITS = " & natural'image(INDEX_BITS);
469 # report "TAG_BITS = " & natural'image(TAG_BITS);
470 # report "WAY_BITS = " & natural'image(WAY_BITS);
475 # Cache reload state machine
483 class RegInternal(RecordObject
):
486 # Cache hit state (Latches for 1 cycle BRAM access)
487 self
.hit_way
= Signal(NUM_WAYS
)
488 self
.hit_nia
= Signal(64)
489 self
.hit_smark
= Signal()
490 self
.hit_valid
= Signal()
492 # Cache miss state (reload state machine)
493 self
.state
= Signal(State
, reset
=State
.IDLE
)
494 self
.wb
= WBMasterOut("wb")
495 self
.req_adr
= Signal(64)
496 self
.store_way
= Signal(NUM_WAYS
)
497 self
.store_index
= Signal(NUM_LINES
)
498 self
.store_row
= Signal(BRAM_ROWS
)
499 self
.store_tag
= Signal(TAG_BITS
)
500 self
.store_valid
= Signal()
501 self
.end_row_ix
= Signal(ROW_LINEBITS
)
502 self
.rows_valid
= RowPerLineValidArray()
505 self
.fetch_failed
= Signal()
507 # -- 64 bit direct mapped icache. All instructions are 4B aligned.
511 # SIM : boolean := false;
512 # -- Line size in bytes
513 # LINE_SIZE : positive := 64;
514 # -- BRAM organisation: We never access more
515 # -- than wishbone_data_bits
516 # -- at a time so to save resources we make the
517 # -- array only that wide,
518 # -- and use consecutive indices for to make a cache "line"
520 # -- ROW_SIZE is the width in bytes of the BRAM (based on WB,
522 # ROW_SIZE : positive := wishbone_data_bits / 8;
523 # -- Number of lines in a set
524 # NUM_LINES : positive := 32;
526 # NUM_WAYS : positive := 4;
527 # -- L1 ITLB number of entries (direct mapped)
528 # TLB_SIZE : positive := 64;
529 # -- L1 ITLB log_2(page_size)
530 # TLB_LG_PGSZ : positive := 12;
531 # -- Number of real address bits that we store
532 # REAL_ADDR_BITS : positive := 56;
533 # -- Non-zero to enable log data collection
534 # LOG_LENGTH : natural := 0
537 # clk : in std_ulogic;
538 # rst : in std_ulogic;
540 # i_in : in Fetch1ToIcacheType;
541 # i_out : out IcacheToDecode1Type;
543 # m_in : in MmuToIcacheType;
545 # stall_in : in std_ulogic;
546 # stall_out : out std_ulogic;
547 # flush_in : in std_ulogic;
548 # inval_in : in std_ulogic;
550 # wishbone_out : out wishbone_master_out;
551 # wishbone_in : in wishbone_slave_out;
553 # log_out : out std_ulogic_vector(53 downto 0)
556 # 64 bit direct mapped icache. All instructions are 4B aligned.
557 class ICache(Elaboratable
):
558 """64 bit direct mapped icache. All instructions are 4B aligned."""
560 self
.i_in
= Fetch1ToICacheType(name
="i_in")
561 self
.i_out
= ICacheToDecode1Type(name
="i_out")
563 self
.m_in
= MMUToICacheType(name
="m_in")
565 self
.stall_in
= Signal()
566 self
.stall_out
= Signal()
567 self
.flush_in
= Signal()
568 self
.inval_in
= Signal()
570 self
.wb_out
= WBMasterOut(name
="wb_out")
571 self
.wb_in
= WBSlaveOut(name
="wb_in")
573 self
.log_out
= Signal(54)
576 # Generate a cache RAM for each way
577 def rams(self
, m
, r
, cache_out_row
, use_previous
, replace_way
, req_row
):
580 wb_in
, stall_in
= self
.wb_in
, self
.stall_in
583 for i
in range(NUM_WAYS
):
584 do_read
= Signal(name
="do_rd_%d" % i
)
585 do_write
= Signal(name
="do_wr_%d" % i
)
586 rd_addr
= Signal(ROW_BITS
)
587 wr_addr
= Signal(ROW_BITS
)
588 d_out
= Signal(ROW_SIZE_BITS
, name
="d_out_%d" % i
)
589 wr_sel
= Signal(ROW_SIZE
)
591 way
= CacheRam(ROW_BITS
, ROW_SIZE_BITS
, True)
592 setattr(m
.submodules
, "cacheram_%d" % i
, way
)
594 comb
+= way
.rd_en
.eq(do_read
)
595 comb
+= way
.rd_addr
.eq(rd_addr
)
596 comb
+= d_out
.eq(way
.rd_data_o
)
597 comb
+= way
.wr_sel
.eq(wr_sel
)
598 comb
+= way
.wr_addr
.eq(wr_addr
)
599 comb
+= way
.wr_data
.eq(wb_in
.dat
)
601 comb
+= do_read
.eq(~
(stall_in | use_previous
))
602 comb
+= do_write
.eq(wb_in
.ack
& (replace_way
== i
))
604 with m
.If(r
.hit_way
== i
):
605 comb
+= cache_out_row
.eq(d_out
)
606 comb
+= rd_addr
.eq(req_row
)
607 comb
+= wr_addr
.eq(r
.store_row
)
608 comb
+= wr_sel
.eq(Repl(do_write
, ROW_SIZE
))
611 def maybe_plrus(self
, m
, r
, plru_victim
):
614 with m
.If(NUM_WAYS
> 1):
615 for i
in range(NUM_LINES
):
616 plru_acc_i
= Signal(WAY_BITS
)
617 plru_acc_en
= Signal()
618 plru
= PLRU(WAY_BITS
)
619 setattr(m
.submodules
, "plru_%d" % i
, plru
)
621 comb
+= plru
.acc_i
.eq(plru_acc_i
)
622 comb
+= plru
.acc_en
.eq(plru_acc_en
)
625 with m
.If(get_index(r
.hit_nia
) == i
):
626 comb
+= plru
.acc_en
.eq(r
.hit_valid
)
628 comb
+= plru
.acc_i
.eq(r
.hit_way
)
629 comb
+= plru_victim
[i
].eq(plru
.lru_o
)
631 # TLB hit detection and real address generation
632 def itlb_lookup(self
, m
, tlb_req_index
, itlb_ptes
, itlb_tags
,
633 real_addr
, itlb_valid_bits
, ra_valid
, eaa_priv
,
634 priv_fault
, access_ok
):
639 pte
= Signal(TLB_PTE_BITS
)
640 ttag
= Signal(TLB_EA_TAG_BITS
)
642 comb
+= tlb_req_index
.eq(hash_ea(i_in
.nia
))
643 comb
+= pte
.eq(itlb_ptes
[tlb_req_index
])
644 comb
+= ttag
.eq(itlb_tags
[tlb_req_index
])
646 with m
.If(i_in
.virt_mode
):
647 comb
+= real_addr
.eq(Cat(
648 i_in
.nia
[:TLB_LG_PGSZ
],
649 pte
[TLB_LG_PGSZ
:REAL_ADDR_BITS
]
652 with m
.If(ttag
== i_in
.nia
[TLB_LG_PGSZ
+ TLB_BITS
:64]):
653 comb
+= ra_valid
.eq(itlb_valid_bits
[tlb_req_index
])
655 comb
+= eaa_priv
.eq(pte
[3])
658 comb
+= real_addr
.eq(i_in
.nia
[:REAL_ADDR_BITS
])
659 comb
+= ra_valid
.eq(1)
660 comb
+= eaa_priv
.eq(1)
662 # No IAMR, so no KUEP support for now
663 comb
+= priv_fault
.eq(eaa_priv
& ~i_in
.priv_mode
)
664 comb
+= access_ok
.eq(ra_valid
& ~priv_fault
)
667 def itlb_update(self
, m
, itlb_valid_bits
, itlb_tags
, itlb_ptes
):
673 wr_index
= Signal(TLB_SIZE
)
674 comb
+= wr_index
.eq(hash_ea(m_in
.addr
))
676 with m
.If(m_in
.tlbie
& m_in
.doall
):
677 # Clear all valid bits
678 for i
in range(TLB_SIZE
):
679 sync
+= itlb_valid_bits
[i
].eq(0)
681 with m
.Elif(m_in
.tlbie
):
682 # Clear entry regardless of hit or miss
683 sync
+= itlb_valid_bits
[wr_index
].eq(0)
685 with m
.Elif(m_in
.tlbld
):
686 sync
+= itlb_tags
[wr_index
].eq(
687 m_in
.addr
[TLB_LG_PGSZ
+ TLB_BITS
:64]
689 sync
+= itlb_ptes
[wr_index
].eq(m_in
.pte
)
690 sync
+= itlb_valid_bits
[wr_index
].eq(1)
692 # Cache hit detection, output to fetch2 and other misc logic
693 def icache_comb(self
, m
, use_previous
, r
, req_index
, req_row
,
694 req_tag
, real_addr
, req_laddr
, cache_valid_bits
,
695 cache_tags
, access_ok
, req_is_hit
,
696 req_is_miss
, replace_way
, plru_victim
, cache_out_row
):
699 #comb += Display("ENTER icache_comb - use_previous:%x req_index:%x "
700 # "req_row:%x req_tag:%x real_addr:%x req_laddr:%x "
701 # "access_ok:%x req_is_hit:%x req_is_miss:%x "
702 # "replace_way:%x", use_previous, req_index, req_row,
703 # req_tag, real_addr, req_laddr, access_ok,
704 # req_is_hit, req_is_miss, replace_way)
706 i_in
, i_out
, wb_out
= self
.i_in
, self
.i_out
, self
.wb_out
707 flush_in
, stall_out
= self
.flush_in
, self
.stall_out
710 hit_way
= Signal(NUM_WAYS
)
712 # i_in.sequential means that i_in.nia this cycle is 4 more than
713 # last cycle. If we read more than 32 bits at a time, had a
714 # cache hit last cycle, and we don't want the first 32-bit chunk
715 # then we can keep the data we read last cycle and just use that.
716 with m
.If(i_in
.nia
[2:INSN_BITS
+2] != 0):
717 comb
+= use_previous
.eq(i_in
.sequential
& r
.hit_valid
)
719 # Extract line, row and tag from request
720 comb
+= req_index
.eq(get_index(i_in
.nia
))
721 comb
+= req_row
.eq(get_row(i_in
.nia
))
722 comb
+= req_tag
.eq(get_tag(real_addr
))
724 # Calculate address of beginning of cache row, will be
725 # used for cache miss processing if needed
726 comb
+= req_laddr
.eq(Cat(
727 Const(0, ROW_OFF_BITS
),
728 real_addr
[ROW_OFF_BITS
:REAL_ADDR_BITS
],
731 # Test if pending request is a hit on any way
733 comb
+= hitcond
.eq((r
.state
== State
.WAIT_ACK
)
734 & (req_index
== r
.store_index
)
735 & r
.rows_valid
[req_row
% ROW_PER_LINE
])
737 cvb
= Signal(NUM_WAYS
)
738 ctag
= Signal(TAG_RAM_WIDTH
)
739 comb
+= ctag
.eq(cache_tags
[req_index
])
740 comb
+= cvb
.eq(cache_valid_bits
[req_index
])
741 for i
in range(NUM_WAYS
):
742 tagi
= Signal(TAG_BITS
, name
="ti%d" % i
)
743 comb
+= tagi
.eq(read_tag(i
, ctag
))
744 hit_test
= Signal(name
="hit_test%d" % i
)
745 comb
+= hit_test
.eq(i
== r
.store_way
)
746 with m
.If((cvb
[i
] |
(hitcond
& hit_test
)) & (tagi
== req_tag
)):
747 comb
+= hit_way
.eq(i
)
750 # Generate the "hit" and "miss" signals
751 # for the synchronous blocks
752 with m
.If(i_in
.req
& access_ok
& ~flush_in
):
753 comb
+= req_is_hit
.eq(is_hit
)
754 comb
+= req_is_miss
.eq(~is_hit
)
756 # The way to replace on a miss
757 with m
.If(r
.state
== State
.CLR_TAG
):
758 comb
+= replace_way
.eq(plru_victim
[r
.store_index
])
760 comb
+= replace_way
.eq(r
.store_way
)
762 # Output instruction from current cache row
764 # Note: This is a mild violation of our design principle of
765 # having pipeline stages output from a clean latch. In this
766 # case we output the result of a mux. The alternative would
767 # be output an entire row which I prefer not to do just yet
768 # as it would force fetch2 to know about some of the cache
769 # geometry information.
770 #comb += Display("BEFORE read_insn_word - r.hit_nia:%x " \
771 # "r.hit_way:%x, cache_out[r.hit_way]:%x", r.hit_nia, \
772 # r.hit_way, cache_out[r.hit_way])
773 comb
+= i_out
.insn
.eq(read_insn_word(r
.hit_nia
, cache_out_row
))
774 comb
+= i_out
.valid
.eq(r
.hit_valid
)
775 comb
+= i_out
.nia
.eq(r
.hit_nia
)
776 comb
+= i_out
.stop_mark
.eq(r
.hit_smark
)
777 comb
+= i_out
.fetch_failed
.eq(r
.fetch_failed
)
779 # Stall fetch1 if we have a miss on cache or TLB
780 # or a protection fault
781 comb
+= stall_out
.eq(~
(is_hit
& access_ok
))
783 # Wishbone requests output (from the cache miss reload machine)
784 comb
+= wb_out
.eq(r
.wb
)
786 # Cache hit synchronous machine
787 def icache_hit(self
, m
, use_previous
, r
, req_is_hit
, req_hit_way
,
788 req_index
, req_tag
, real_addr
):
791 i_in
, stall_in
= self
.i_in
, self
.stall_in
792 flush_in
= self
.flush_in
794 # keep outputs to fetch2 unchanged on a stall
795 # except that flush or reset sets valid to 0
796 # If use_previous, keep the same data as last
797 # cycle and use the second half
798 with m
.If(stall_in | use_previous
):
800 sync
+= r
.hit_valid
.eq(0)
802 # On a hit, latch the request for the next cycle,
803 # when the BRAM data will be available on the
804 # cache_out output of the corresponding way
805 sync
+= r
.hit_valid
.eq(req_is_hit
)
807 with m
.If(req_is_hit
):
808 sync
+= r
.hit_way
.eq(req_hit_way
)
809 sync
+= Display("cache hit nia:%x IR:%x SM:%x idx:%x " \
810 "tag:%x way:%x RA:%x", i_in
.nia
, \
811 i_in
.virt_mode
, i_in
.stop_mark
, req_index
, \
812 req_tag
, req_hit_way
, real_addr
)
816 with m
.If(~stall_in
):
817 # Send stop marks and NIA down regardless of validity
818 sync
+= r
.hit_smark
.eq(i_in
.stop_mark
)
819 sync
+= r
.hit_nia
.eq(i_in
.nia
)
821 # Cache miss/reload synchronous machine
822 def icache_miss(self
, m
, cache_valid_bits
, r
, req_is_miss
,
823 req_index
, req_laddr
, req_tag
, replace_way
,
824 cache_tags
, access_ok
, real_addr
):
828 i_in
, wb_in
, m_in
= self
.i_in
, self
.wb_in
, self
.m_in
829 stall_in
, flush_in
= self
.stall_in
, self
.flush_in
830 inval_in
= self
.inval_in
832 # variable tagset : cache_tags_set_t;
833 # variable stbs_done : boolean;
835 tagset
= Signal(TAG_RAM_WIDTH
)
838 comb
+= r
.wb
.sel
.eq(-1)
839 comb
+= r
.wb
.adr
.eq(r
.req_adr
[3:])
841 # Process cache invalidations
843 for i
in range(NUM_LINES
):
844 sync
+= cache_valid_bits
[i
].eq(0)
845 sync
+= r
.store_valid
.eq(0)
848 with m
.Switch(r
.state
):
850 with m
.Case(State
.IDLE
):
851 # Reset per-row valid flags,
852 # only used in WAIT_ACK
853 for i
in range(ROW_PER_LINE
):
854 sync
+= r
.rows_valid
[i
].eq(0)
856 # We need to read a cache line
857 with m
.If(req_is_miss
):
858 sync
+= Display("cache miss nia:%x IR:%x SM:%x idx:%x "
859 " way:%x tag:%x RA:%x", i_in
.nia
,
860 i_in
.virt_mode
, i_in
.stop_mark
, req_index
,
861 replace_way
, req_tag
, real_addr
)
863 # Keep track of our index and way
864 # for subsequent stores
865 st_row
= Signal(BRAM_ROWS
)
866 comb
+= st_row
.eq(get_row(req_laddr
))
867 sync
+= r
.store_index
.eq(req_index
)
868 sync
+= r
.store_row
.eq(st_row
)
869 sync
+= r
.store_tag
.eq(req_tag
)
870 sync
+= r
.store_valid
.eq(1)
871 sync
+= r
.end_row_ix
.eq(get_row_of_line(st_row
) - 1)
873 # Prep for first wishbone read. We calculate the
874 # address of the start of the cache line and
875 # start the WB cycle.
876 sync
+= r
.req_adr
.eq(req_laddr
)
877 sync
+= r
.wb
.cyc
.eq(1)
878 sync
+= r
.wb
.stb
.eq(1)
880 # Track that we had one request sent
881 sync
+= r
.state
.eq(State
.CLR_TAG
)
883 with m
.Case(State
.CLR_TAG
, State
.WAIT_ACK
):
884 with m
.If(r
.state
== State
.CLR_TAG
):
885 # Get victim way from plru
886 sync
+= r
.store_way
.eq(replace_way
)
887 # Force misses on that way while reloading that line
888 cv
= Signal(INDEX_BITS
)
889 comb
+= cv
.eq(cache_valid_bits
[req_index
])
890 comb
+= cv
.bit_select(replace_way
, 1).eq(0)
891 sync
+= cache_valid_bits
[req_index
].eq(cv
)
893 for i
in range(NUM_WAYS
):
894 with m
.If(i
== replace_way
):
895 comb
+= tagset
.eq(cache_tags
[r
.store_index
])
896 comb
+= write_tag(i
, tagset
, r
.store_tag
)
897 sync
+= cache_tags
[r
.store_index
].eq(tagset
)
899 sync
+= r
.state
.eq(State
.WAIT_ACK
)
901 # Requests are all sent if stb is 0
903 comb
+= stbs_zero
.eq(r
.wb
.stb
== 0)
904 comb
+= stbs_done
.eq(stbs_zero
)
906 # If we are still sending requests, was one accepted?
907 with m
.If(~wb_in
.stall
& ~stbs_zero
):
908 # That was the last word ? # We are done sending.
909 # Clear stb and set stbs_done # so we can handle
910 # an eventual last ack on # the same cycle.
911 with m
.If(is_last_row_addr(r
.req_adr
, r
.end_row_ix
)):
912 sync
+= Display("IS_LAST_ROW_ADDR " \
913 "r.wb.addr:%x r.end_row_ix:%x " \
914 "r.wb.stb:%x stbs_zero:%x " \
915 "stbs_done:%x", r
.wb
.adr
, \
916 r
.end_row_ix
, r
.wb
.stb
, \
917 stbs_zero
, stbs_done
)
918 sync
+= r
.wb
.stb
.eq(0)
919 comb
+= stbs_done
.eq(1)
921 # Calculate the next row address
922 rarange
= Signal(LINE_OFF_BITS
- ROW_OFF_BITS
)
924 r
.req_adr
[ROW_OFF_BITS
:LINE_OFF_BITS
] + 1
926 sync
+= r
.req_adr
[ROW_OFF_BITS
:LINE_OFF_BITS
].eq(
929 sync
+= Display("RARANGE r.req_adr:%x rarange:%x "
930 "stbs_zero:%x stbs_done:%x",
931 r
.req_adr
, rarange
, stbs_zero
, stbs_done
)
933 # Incoming acks processing
934 with m
.If(wb_in
.ack
):
935 sync
+= Display("WB_IN_ACK data:%x stbs_zero:%x "
937 wb_in
.dat
, stbs_zero
, stbs_done
)
939 sync
+= r
.rows_valid
[r
.store_row
% ROW_PER_LINE
].eq(1)
941 # Check for completion
942 with m
.If(stbs_done
&
943 is_last_row(r
.store_row
, r
.end_row_ix
)):
944 # Complete wishbone cycle
945 sync
+= r
.wb
.cyc
.eq(0)
947 # Cache line is now valid
948 cv
= Signal(INDEX_BITS
)
949 comb
+= cv
.eq(cache_valid_bits
[r
.store_index
])
950 comb
+= cv
.bit_select(replace_way
, 1).eq(
951 r
.store_valid
& ~inval_in
953 sync
+= cache_valid_bits
[r
.store_index
].eq(cv
)
955 sync
+= r
.state
.eq(State
.IDLE
)
957 # Increment store row counter
958 sync
+= r
.store_row
.eq(next_row(r
.store_row
))
960 # TLB miss and protection fault processing
961 with m
.If(flush_in | m_in
.tlbld
):
962 sync
+= r
.fetch_failed
.eq(0)
963 with m
.Elif(i_in
.req
& ~access_ok
& ~stall_in
):
964 sync
+= r
.fetch_failed
.eq(1)
966 # icache_log: if LOG_LENGTH > 0 generate
967 def icache_log(self
, m
, req_hit_way
, ra_valid
, access_ok
,
968 req_is_miss
, req_is_hit
, lway
, wstate
, r
):
972 wb_in
, i_out
= self
.wb_in
, self
.i_out
973 log_out
, stall_out
= self
.log_out
, self
.stall_out
975 # -- Output data to logger
976 # signal log_data : std_ulogic_vector(53 downto 0);
978 # data_log: process(clk)
979 # variable lway: way_t;
980 # variable wstate: std_ulogic;
981 # Output data to logger
982 for i
in range(LOG_LENGTH
):
983 # Output data to logger
984 log_data
= Signal(54)
985 lway
= Signal(NUM_WAYS
)
989 # if rising_edge(clk) then
990 # lway := req_hit_way;
992 sync
+= lway
.eq(req_hit_way
)
995 # if r.state /= IDLE then
998 with m
.If(r
.state
!= State
.IDLE
):
1001 # log_data <= i_out.valid &
1004 # r.wb.adr(5 downto 3) &
1005 # r.wb.stb & r.wb.cyc &
1006 # wishbone_in.stall &
1009 # r.hit_nia(5 downto 2) &
1011 # std_ulogic_vector(to_unsigned(lway, 3)) &
1012 # req_is_hit & req_is_miss &
1015 sync
+= log_data
.eq(Cat(
1016 ra_valid
, access_ok
, req_is_miss
, req_is_hit
,
1017 lway
, wstate
, r
.hit_nia
[2:6],
1018 r
.fetch_failed
, stall_out
, wb_in
.stall
, r
.wb
.cyc
,
1019 r
.wb
.stb
, r
.wb
.adr
[3:6], wb_in
.ack
, i_out
.insn
,
1024 # log_out <= log_data;
1025 comb
+= log_out
.eq(log_data
)
1029 def elaborate(self
, platform
):
1034 # Storage. Hopefully "cache_rows" is a BRAM, the rest is LUTs
1035 cache_tags
= CacheTagArray()
1036 cache_valid_bits
= CacheValidBitsArray()
1038 # signal itlb_valids : tlb_valids_t;
1039 # signal itlb_tags : tlb_tags_t;
1040 # signal itlb_ptes : tlb_ptes_t;
1041 # attribute ram_style of itlb_tags : signal is "distributed";
1042 # attribute ram_style of itlb_ptes : signal is "distributed";
1043 itlb_valid_bits
= TLBValidBitsArray()
1044 itlb_tags
= TLBTagArray()
1045 itlb_ptes
= TLBPtesArray()
1046 # TODO to be passed to nmigen as ram attributes
1047 # attribute ram_style of itlb_tags : signal is "distributed";
1048 # attribute ram_style of itlb_ptes : signal is "distributed";
1050 # -- Privilege bit from PTE EAA field
1051 # signal eaa_priv : std_ulogic;
1052 # Privilege bit from PTE EAA field
1055 # signal r : reg_internal_t;
1058 # -- Async signals on incoming request
1059 # signal req_index : index_t;
1060 # signal req_row : row_t;
1061 # signal req_hit_way : way_t;
1062 # signal req_tag : cache_tag_t;
1063 # signal req_is_hit : std_ulogic;
1064 # signal req_is_miss : std_ulogic;
1065 # signal req_laddr : std_ulogic_vector(63 downto 0);
1066 # Async signal on incoming request
1067 req_index
= Signal(NUM_LINES
)
1068 req_row
= Signal(BRAM_ROWS
)
1069 req_hit_way
= Signal(NUM_WAYS
)
1070 req_tag
= Signal(TAG_BITS
)
1071 req_is_hit
= Signal()
1072 req_is_miss
= Signal()
1073 req_laddr
= Signal(64)
1075 # signal tlb_req_index : tlb_index_t;
1076 # signal real_addr : std_ulogic_vector(
1077 # REAL_ADDR_BITS - 1 downto 0
1079 # signal ra_valid : std_ulogic;
1080 # signal priv_fault : std_ulogic;
1081 # signal access_ok : std_ulogic;
1082 # signal use_previous : std_ulogic;
1083 tlb_req_index
= Signal(TLB_SIZE
)
1084 real_addr
= Signal(REAL_ADDR_BITS
)
1086 priv_fault
= Signal()
1087 access_ok
= Signal()
1088 use_previous
= Signal()
1090 # signal cache_out : cache_ram_out_t;
1091 cache_out_row
= Signal(ROW_SIZE_BITS
)
1093 # signal plru_victim : plru_out_t;
1094 # signal replace_way : way_t;
1095 plru_victim
= PLRUOut()
1096 replace_way
= Signal(NUM_WAYS
)
1098 # call sub-functions putting everything together, using shared
1099 # signals established above
1100 self
.rams(m
, r
, cache_out_row
, use_previous
, replace_way
, req_row
)
1101 self
.maybe_plrus(m
, r
, plru_victim
)
1102 self
.itlb_lookup(m
, tlb_req_index
, itlb_ptes
, itlb_tags
,
1103 real_addr
, itlb_valid_bits
, ra_valid
, eaa_priv
,
1104 priv_fault
, access_ok
)
1105 self
.itlb_update(m
, itlb_valid_bits
, itlb_tags
, itlb_ptes
)
1106 self
.icache_comb(m
, use_previous
, r
, req_index
, req_row
,
1107 req_tag
, real_addr
, req_laddr
, cache_valid_bits
,
1108 cache_tags
, access_ok
, req_is_hit
, req_is_miss
,
1109 replace_way
, plru_victim
, cache_out_row
)
1110 self
.icache_hit(m
, use_previous
, r
, req_is_hit
, req_hit_way
,
1111 req_index
, req_tag
, real_addr
)
1112 self
.icache_miss(m
, cache_valid_bits
, r
, req_is_miss
, req_index
,
1113 req_laddr
, req_tag
, replace_way
, cache_tags
,
1114 access_ok
, real_addr
)
1115 #self.icache_log(m, log_out, req_hit_way, ra_valid, access_ok,
1116 # req_is_miss, req_is_hit, lway, wstate, r)
1124 # use ieee.std_logic_1164.all;
1127 # use work.common.all;
1128 # use work.wishbone_types.all;
1130 # entity icache_tb is
1133 # architecture behave of icache_tb is
1134 # signal clk : std_ulogic;
1135 # signal rst : std_ulogic;
1137 # signal i_out : Fetch1ToIcacheType;
1138 # signal i_in : IcacheToDecode1Type;
1140 # signal m_out : MmuToIcacheType;
1142 # signal wb_bram_in : wishbone_master_out;
1143 # signal wb_bram_out : wishbone_slave_out;
1145 # constant clk_period : time := 10 ns;
1147 # icache0: entity work.icache
1161 # wishbone_out => wb_bram_in,
1162 # wishbone_in => wb_bram_out
1165 # -- BRAM Memory slave
1166 # bram0: entity work.wishbone_bram_wrapper
1168 # MEMORY_SIZE => 1024,
1169 # RAM_INIT_FILE => "icache_test.bin"
1174 # wishbone_in => wb_bram_in,
1175 # wishbone_out => wb_bram_out
1178 # clk_process: process
1181 # wait for clk_period/2;
1183 # wait for clk_period/2;
1186 # rst_process: process
1189 # wait for 2*clk_period;
1197 # i_out.nia <= (others => '0');
1198 # i_out.stop_mark <= '0';
1200 # m_out.tlbld <= '0';
1201 # m_out.tlbie <= '0';
1202 # m_out.addr <= (others => '0');
1203 # m_out.pte <= (others => '0');
1205 # wait until rising_edge(clk);
1206 # wait until rising_edge(clk);
1207 # wait until rising_edge(clk);
1208 # wait until rising_edge(clk);
1211 # i_out.nia <= x"0000000000000004";
1213 # wait for 30*clk_period;
1214 # wait until rising_edge(clk);
1216 # assert i_in.valid = '1' severity failure;
1217 # assert i_in.insn = x"00000001"
1218 # report "insn @" & to_hstring(i_out.nia) &
1219 # "=" & to_hstring(i_in.insn) &
1220 # " expected 00000001"
1225 # wait until rising_edge(clk);
1229 # i_out.nia <= x"0000000000000008";
1230 # wait until rising_edge(clk);
1231 # wait until rising_edge(clk);
1232 # assert i_in.valid = '1' severity failure;
1233 # assert i_in.insn = x"00000002"
1234 # report "insn @" & to_hstring(i_out.nia) &
1235 # "=" & to_hstring(i_in.insn) &
1236 # " expected 00000002"
1238 # wait until rising_edge(clk);
1242 # i_out.nia <= x"0000000000000040";
1244 # wait for 30*clk_period;
1245 # wait until rising_edge(clk);
1247 # assert i_in.valid = '1' severity failure;
1248 # assert i_in.insn = x"00000010"
1249 # report "insn @" & to_hstring(i_out.nia) &
1250 # "=" & to_hstring(i_in.insn) &
1251 # " expected 00000010"
1254 # -- test something that aliases
1256 # i_out.nia <= x"0000000000000100";
1257 # wait until rising_edge(clk);
1258 # wait until rising_edge(clk);
1259 # assert i_in.valid = '0' severity failure;
1260 # wait until rising_edge(clk);
1262 # wait for 30*clk_period;
1263 # wait until rising_edge(clk);
1265 # assert i_in.valid = '1' severity failure;
1266 # assert i_in.insn = x"00000040"
1267 # report "insn @" & to_hstring(i_out.nia) &
1268 # "=" & to_hstring(i_in.insn) &
1269 # " expected 00000040"
1277 def icache_sim(dut
):
1282 yield i_in
.valid
.eq(0)
1283 yield i_out
.priv_mode
.eq(1)
1284 yield i_out
.req
.eq(0)
1285 yield i_out
.nia
.eq(0)
1286 yield i_out
.stop_mark
.eq(0)
1287 yield m_out
.tlbld
.eq(0)
1288 yield m_out
.tlbie
.eq(0)
1289 yield m_out
.addr
.eq(0)
1290 yield m_out
.pte
.eq(0)
1295 yield i_out
.req
.eq(1)
1296 yield i_out
.nia
.eq(Const(0x0000000000000004, 64))
1300 valid
= yield i_in
.valid
1301 nia
= yield i_out
.nia
1302 insn
= yield i_in
.insn
1303 print(f
"valid? {valid}")
1305 assert insn
== 0x00000001, \
1306 "insn @%x=%x expected 00000001" % (nia
, insn
)
1307 yield i_out
.req
.eq(0)
1311 yield i_out
.req
.eq(1)
1312 yield i_out
.nia
.eq(Const(0x0000000000000008, 64))
1315 valid
= yield i_in
.valid
1316 nia
= yield i_in
.nia
1317 insn
= yield i_in
.insn
1319 assert insn
== 0x00000002, \
1320 "insn @%x=%x expected 00000002" % (nia
, insn
)
1324 yield i_out
.req
.eq(1)
1325 yield i_out
.nia
.eq(Const(0x0000000000000040, 64))
1329 valid
= yield i_in
.valid
1330 nia
= yield i_out
.nia
1331 insn
= yield i_in
.insn
1333 assert insn
== 0x00000010, \
1334 "insn @%x=%x expected 00000010" % (nia
, insn
)
1336 # test something that aliases
1337 yield i_out
.req
.eq(1)
1338 yield i_out
.nia
.eq(Const(0x0000000000000100, 64))
1341 valid
= yield i_in
.valid
1346 insn
= yield i_in
.insn
1347 valid
= yield i_in
.valid
1348 insn
= yield i_in
.insn
1350 assert insn
== 0x00000040, \
1351 "insn @%x=%x expected 00000040" % (nia
, insn
)
1352 yield i_out
.req
.eq(0)
1356 def test_icache(mem
):
1359 memory
= Memory(width
=64, depth
=16*64, init
=mem
)
1360 sram
= SRAM(memory
=memory
, granularity
=8)
1364 m
.submodules
.icache
= dut
1365 m
.submodules
.sram
= sram
1367 m
.d
.comb
+= sram
.bus
.cyc
.eq(dut
.wb_out
.cyc
)
1368 m
.d
.comb
+= sram
.bus
.stb
.eq(dut
.wb_out
.stb
)
1369 m
.d
.comb
+= sram
.bus
.we
.eq(dut
.wb_out
.we
)
1370 m
.d
.comb
+= sram
.bus
.sel
.eq(dut
.wb_out
.sel
)
1371 m
.d
.comb
+= sram
.bus
.adr
.eq(dut
.wb_out
.adr
)
1372 m
.d
.comb
+= sram
.bus
.dat_w
.eq(dut
.wb_out
.dat
)
1374 m
.d
.comb
+= dut
.wb_in
.ack
.eq(sram
.bus
.ack
)
1375 m
.d
.comb
+= dut
.wb_in
.dat
.eq(sram
.bus
.dat_r
)
1381 sim
.add_sync_process(wrap(icache_sim(dut
)))
1382 with sim
.write_vcd('test_icache.vcd'):
1385 if __name__
== '__main__':
1387 vl
= rtlil
.convert(dut
, ports
=[])
1388 with
open("test_icache.il", "w") as f
:
1392 for i
in range(512):
1393 mem
.append((i
*2)|
((i
*2+1)<<32))