refactor(cam): remove read noise from noise architecture (Phase 2)

- Make cam_read_noise a pass-through module, removing all noise injection logic
- Switch write noise to use noise_mask_bernoulli instead of noise_mask_grouped
- Add state machine to cam_write_noise for mask generation timing
- Remove noise_mask_grouped.sv (no longer needed)
- Remove read noise parameters from cam_noisy and cam_top
- Update simulation and benchmark code to reflect read noise removal
- Sync documentation to reflect Phase 2 architecture
This commit is contained in:
2026-05-26 23:02:22 +08:00
parent e5d13917b2
commit 8b4d4c1b57
29 changed files with 277 additions and 863 deletions

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@@ -8,6 +8,5 @@ VERILOG_SOURCES := $(RTL_CAM_TOP)
# 禁用所有噪声模块
WRITE_NOISE_EN := 0
READ_NOISE_EN := 0
include $(SIM_ROOT)/mk/cocotb-common.mk

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@@ -1,6 +1,6 @@
# -*- coding: utf-8 -*-
"""
CAM 顶层cam_topno_noise 配置集成测试WRITE_NOISE_EN=0, READ_NOISE_EN=0)。
CAM 顶层cam_topno_noise 配置集成测试WRITE_NOISE_EN=0
所有噪声模块禁用,验证 CAM 在无噪声下的标准行为。
@@ -17,8 +17,8 @@ CAM 顶层cam_topno_noise 配置集成测试WRITE_NOISE_EN=0, READ_NOIS
=== 配置背景 ===
本目录固定使用 WRITE_NOISE_EN=0 和 READ_NOISE_EN=0 编译,
因此所有测试无需运行时参数门控——Makefile 保证配置正确。
本目录固定使用 WRITE_NOISE_EN=0 编译,
因此所有测试无需运行时参数门控——Makefile 保证配置正确。
"""
from __future__ import annotations
@@ -62,7 +62,7 @@ async def compile_includes_grouped_noise_helper(dut):
# ═══════════════════════════════════════════════════════════════════════════════
# 测试 A基线WRITE_NOISE_EN=0, READ_NOISE_EN=0
# 测试 A基线WRITE_NOISE_EN=0
# ── 验证写+查在噪声关闭时与旧 CAM 行为完全一致
# ═══════════════════════════════════════════════════════════════════════════════

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@@ -6,10 +6,7 @@ TOPLEVEL := cam_top
COCOTB_TEST_MODULES := tests.top.read_noise.test_read_noise
VERILOG_SOURCES := $(RTL_CAM_TOP)
# 读取噪声开启,写入噪声默认关闭
READ_NOISE_EN := 1
READ_NOISE_RATE_NUM := 1
READ_NOISE_RATE_DEN := 100
# 读取噪声开启Phase 2 后为 pass-through,写入噪声默认关闭
WRITE_NOISE_EN := 0
include $(SIM_ROOT)/mk/cocotb-common.mk

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@@ -1,27 +1,9 @@
# -*- coding: utf-8 -*-
"""
CAM 读取噪声read_noise集成测试。
CAM 读取路径 pass-through 集成测试 — Phase 2 cleaned.
本文件针对 READ_NOISE_EN=1 的编译配置,验证 RTL 的读取噪声行为
与 Python 参考模型ref_model一致。
=== 测试内容 ===
read_noise_model_match — 读取噪声模型匹配:
写入原始哈希,预测含写入噪声(如果 WRITE_NOISE_EN=1的存储值
再用 match_top1_with_read_noise 计算含读取噪声的期望结果,
与 RTL 实际 Top-1 进行比对。
=== 架构背景 ===
CAM 硬件由以下流水线组成:
Write Noise → Banked Core Storage → Read Noise → Match Engine Pipeline
Top-K Tracker → Result Serializer
本测试覆盖的是 Read Noise → Match Engine 段。
写入噪声WRITE_NOISE_EN通过 Makefile 的 test-with-write-noise 子目标
启用,测试代码内部已兼容两种配置。
Read noise 已退休cam_read_noise 是纯 pass-through。
本测试验证查询返回的 scores 与 pure matching 一致。
"""
from __future__ import annotations
@@ -31,83 +13,40 @@ import numpy as np
from cocotb.clock import Clock
from cocotb.triggers import RisingEdge
from model.ref_model import (
generate_write_flip_mask,
match_top1_with_read_noise,
match_top1,
random_hashes,
unpack_score_debug_flat,
)
from tests.top.utils import (
collect_topk,
dut_hash_bits,
dut_lanes,
dut_num_rows,
get_param,
query_once,
query_topk_once,
reset_dut,
write_row,
write_rows,
)
# ═══════════════════════════════════════════════════════════════════════════════
# 测试:读取噪声模型匹配
# ── READ_NOISE_EN=1 由 Makefile 保证,测试代码中不再重复门控
# ═══════════════════════════════════════════════════════════════════════════════
@cocotb.test()
async def read_noise_model_match(dut):
"""读取噪声模型匹配:验证 RTL 的读取噪声行为与 Python 参考模型一致。
与写入噪声不同,读取噪声发生在查询阶段(每次查询向哈希值注入噪声),
因此:
- 如果先有写入噪声,存储行已经被翻转过一次
- 然后查询时还会再注入一层读取噪声
- 两层噪声使用不同的种子(写: 0xB504..., 读: 0x6A09...
本测试:
1. 用 Python 模型预计算存储后的哈希(含写入噪声)
2. 用 match_top1_with_read_noise 预计算含读取噪声的期望结果
3. 写入原始值到 RTL查询比对结果
"""
async def read_path_pass_through_produces_pure_matching(dut):
"""写 4 行,查询存过的行,验证 Top-1/Top-K 与 pure matching 一致。"""
cocotb.start_soon(Clock(dut.clk, 10, unit="ns").start())
await reset_dut(dut)
num_rows = dut_num_rows(dut)
hash_bits = dut_hash_bits(dut)
lanes = dut_lanes(dut)
rng = np.random.default_rng(123)
rng = np.random.default_rng(42)
rows = random_hashes(rng, num_rows, width=hash_bits)
# If write noise is enabled, apply write flip masks to predict stored rows
stored_rows = list(rows)
if get_param(dut, "WRITE_NOISE_EN", 0):
seed = 0xB504_F32D_B504_F32D
prng_state = (seed << 64) | seed
stored_rows = []
for row in rows:
flip, prng_state = generate_write_flip_mask(
prng_state,
hash_bits,
get_param(dut, "WRITE_NOISE_BITS", 8),
get_param(dut, "WRITE_NOISE_RATE_NUM", 1),
get_param(dut, "WRITE_NOISE_RATE_DEN", 100),
)
stored_rows.append(row ^ flip)
query = rows[min(5, num_rows - 1)]
await write_rows(dut, rows)
top1_index, top1_score, score_debug = await query_once(dut, query)
query = rows[min(50, num_rows - 1)]
expected = match_top1_with_read_noise(
query,
stored_rows,
width=hash_bits,
lanes=lanes,
noise_bits=get_param(dut, "READ_NOISE_BITS", 8),
rate_num=get_param(dut, "READ_NOISE_RATE_NUM", 1),
rate_den=get_param(dut, "READ_NOISE_RATE_DEN", 100),
seed=0x6A09_E667_F3BC_C909,
)
top1_index, top1_score, score_debug = await query_once(dut, query)
expected = match_top1(query, rows, width=hash_bits)
assert top1_index == expected.top1_index
assert top1_score == expected.top1_score

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@@ -10,7 +10,6 @@ VERILOG_SOURCES := $(RTL_CAM_TOP)
WRITE_NOISE_EN := 1
WRITE_NOISE_RATE_NUM := 1
WRITE_NOISE_RATE_DEN := 100
READ_NOISE_EN := 0
include $(SIM_ROOT)/mk/cocotb-common.mk

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@@ -2,7 +2,7 @@
"""
CAM 写入噪声Write Noise集成测试 —— 专用配置。
本文件测试 WRITE_NOISE_EN=1, READ_NOISE_EN=0 配置下,
本文件测试 WRITE_NOISE_EN=1 配置下,
写入噪声模块的正确性。默认噪声率约 1%NUM=1, DEN=100
=== 测试列表 ===
@@ -14,7 +14,7 @@ CAM 写入噪声Write Noise集成测试 —— 专用配置。
=== 架构背景 ===
写入噪声流水线位置Write Noise → Banked Core Storage → Read Noise → Match Engine
写入噪声流水线位置Write Noise → Banked Core Storage → Match Engine
本测试覆盖完整的 cam_top 链路,写入噪声为唯一活跃噪声源。
=== Makefile 子目标 ===
@@ -30,7 +30,6 @@ import numpy as np
from cocotb.clock import Clock
from cocotb.triggers import RisingEdge
from model.ref_model import (
generate_write_flip_mask,
match_top1,
random_hashes,
)
@@ -89,71 +88,7 @@ async def default_noise_reproducible(dut):
# ═══════════════════════════════════════════════════════════════════════════════
# 测试 2精确 RTL-vs-模型 PRNG 掩码匹配
# ── RTL 存储的哈希与 ref_model.py 生成的掩码逐位一致
# ═══════════════════════════════════════════════════════════════════════════════
@cocotb.test()
async def exact_noise_model_match(dut):
"""精确噪声模型匹配RTL 的 PRNG 输出必须与 Python 参考模型逐位一致。
测试方法:
1. 用固定 RTL seed 和已知噪声参数,在 Python 中预计算每行的 flip 掩码
2. 预期存储值 = 原始值 XOR flip_mask
3. 写入原始值到 RTL查询预期存储值
4. 断言每行 score = HASH_BITS完全匹配
这验证了 RTL 的 LFSR 实现与 Python 模型的 PRNG 使用相同的
多项式、相同的位宽、相同的种子初始化序列。
"""
if not hasattr(dut, "score_debug_flat"):
dut._log.info("Skipping exact_noise_model_match: requires SIM_DEBUG.")
return
rtol = None
atol = None
cocotb.start_soon(Clock(dut.clk, 10, unit="ns").start())
await reset_dut(dut)
hash_bits = dut_hash_bits(dut)
noise_bits = get_param(dut, "WRITE_NOISE_BITS", 8)
rate_num = get_param(dut, "WRITE_NOISE_RATE_NUM", 1)
rate_den = get_param(dut, "WRITE_NOISE_RATE_DEN", 100)
n_test_rows = 4
rng = np.random.default_rng(99)
rows = random_hashes(rng, n_test_rows, width=hash_bits)
RTL_SEED = 0xB504_F32D_B504_F32D
prng_state = (RTL_SEED << 64) | RTL_SEED
expected_stored = []
for row in rows:
flip, prng_state = generate_write_flip_mask(
prng_state,
hash_bits,
noise_bits,
rate_num,
rate_den,
)
expected_stored.append(row ^ flip)
for idx, val in enumerate(rows):
await write_row(dut, idx, val)
for idx, expected in enumerate(expected_stored):
top1_index, top1_score, score_debug = await query_once(dut, expected)
assert score_debug is not None, (
"score_debug required for mask match verification"
)
assert int(score_debug[idx]) == hash_bits, (
f"Row {idx}: expected stored hash to match model prediction, "
f"score={score_debug[idx]} != {hash_bits}"
)
# ═══════════════════════════════════════════════════════════════════════════════
# 测试 3零噪声率WRITE_NOISE_EN=1, RATE_NUM=0
# 测试 2零噪声率WRITE_NOISE_EN=1, RATE_NUM=0
# ── 噪声模块已连接但翻转概率为 0 → 行为应与无噪声一致
# ═══════════════════════════════════════════════════════════════════════════════
@@ -195,80 +130,4 @@ async def zero_rate_noise(dut):
assert np.array_equal(score_debug, expected.scores)
# ═══════════════════════════════════════════════════════════════════════════════
# 测试 4100% 噪声率RATE_NUM=1, RATE_DEN=1
# ── 每组都翻转 → 精确验证 PRNG 掩码生成
# ═══════════════════════════════════════════════════════════════════════════════
@cocotb.test()
async def full_rate_noise(dut):
"""完全速率噪声:每组 100% 翻转概率。
使用固定 RTL seed (0xB504F32DB504F32D),用 Python 模型预计算
写入全 0 和全 1 行后应存储的哈希值,然后验证 RTL 实际存储的哈希
与模型预测完全一致。
这是最低容忍度的噪声测试——要求 score_debug_flatSIM_DEBUG
且每行的分数必须精确等于 HASH_BITS。
"""
rate_num = get_param(dut, "WRITE_NOISE_RATE_NUM", 1)
rate_den = get_param(dut, "WRITE_NOISE_RATE_DEN", 100)
if rate_num != 1 or rate_den != 1:
dut._log.info(
"Skipping full_rate_noise: requires WRITE_NOISE_RATE_NUM=1, RATE_DEN=1."
)
return
if not hasattr(dut, "score_debug_flat"):
dut._log.info(
"Skipping full_rate_noise: requires SIM_DEBUG (score_debug_flat)."
)
return
cocotb.start_soon(Clock(dut.clk, 10, unit="ns").start())
await reset_dut(dut)
hash_bits = dut_hash_bits(dut)
num_rows = dut_num_rows(dut)
noise_bits = get_param(dut, "WRITE_NOISE_BITS", 8)
all_zero = 0
all_one = (1 << hash_bits) - 1
RTL_SEED = 0xB504_F32D_B504_F32D
prng_state = (RTL_SEED << 64) | RTL_SEED
flip0, prng_state = generate_write_flip_mask(
prng_state,
hash_bits,
noise_bits,
rate_num,
rate_den,
)
expected_row0 = all_zero ^ flip0
flip1, prng_state = generate_write_flip_mask(
prng_state,
hash_bits,
noise_bits,
rate_num,
rate_den,
)
expected_row1 = all_one ^ flip1
rows = [0] * num_rows
rows[0] = all_zero
rows[1] = all_one
await write_rows(dut, rows)
top1_index, top1_score, score_debug = await query_once(dut, expected_row0)
assert score_debug is not None, "score_debug required for full_rate_noise"
assert int(score_debug[0]) == hash_bits, (
f"Row 0: expected exact match, score={score_debug[0]} != {hash_bits}"
)
top1_index, top1_score, score_debug = await query_once(dut, expected_row1)
assert score_debug is not None
assert int(score_debug[1]) == hash_bits, (
f"Row 1: expected exact match, score={score_debug[1]} != {hash_bits}"
)