diff --git a/ARCHITECTURE.md b/ARCHITECTURE.md
index 78445e7..20c1db3 100644
--- a/ARCHITECTURE.md
+++ b/ARCHITECTURE.md
@@ -40,8 +40,9 @@ LTC2980 margin 控制器。TTL 只負責「按順序 `sendln` 並把畫面收進
 | BMC 存取 | host 端 `bmc-manager run "<cmd>"`（不需對 BMC 開 SSH，繞開其 busybox 工具鏈）；`bmc-first-enroll` / `bmc-manager version\|status` |
 | 背景工作管理 | `bgctl run/list/stop --all/reset`（平台工具）；長時間 ping 用 `systemd-run --unit=` 掛成 transient unit |
 | 管理網路 | iproute2（`ip link set` / `ip address replace` / `ip route replace ... metric`）+ `ping -I` |
-| 測試 session | `hw-test-session start\|log\|status\|finish`；job log 收在 `/host/hw-eval/current/jobs/` |
+| 測試 session | `hw-test-session start\|log\|status\|finish`；job log 收在 `/host/hw-eval/jobs/` |
 | 風扇控制 | max31790 driver rebind（`/sys/bus/i2c/drivers/max31790/{bind,unbind}`）+ `fan-speed-control.sh <%>` |
+| 100G PRBS | `bcmcmd -n <unit> -c 'dsh -c "phy diag <phy> prbs …"'`（set / prbsstat STArt / get / Ber / STOp / clear） |
 | 壓力測試 | `mlucas-avx2`（AMD CPU）、`bgctl run` 排程的 `memtester` / `qfx5252-stress-ssd` / `qfx5252-stress-usb` |
 | 資料面流量 | `bcmcmd`（Broadcom drivshell）VLAN loopback + `tx` burst，switch unit 0 / 1 |
 | 流量報表 | DUT 上 awk（`blanton_traffic_linespeed report`）；離線 `python3 tools/bcm_mibpair_report_V1.1.0.py` |
@@ -177,7 +178,10 @@ Blanton_TTL_Script/
             ├── blanton_traffic_linespeed.sh  # SWB loopback 線速流量（bcmcmd unit 0/1）
             │                                 #   init/clear/show/start/stop/ps/report/run
             ├── mgmt_ping_monitor.sh       # 10G/1G 管理網路 ping 監控（iproute2）
-            │                              #   eth0→TARGET_10G、eth1→TARGET_1G，兩張卡都保持 up
+            │                              #   eth0→TARGET_10G、eth1→TARGET_1G，兩張卡同時持續 ping
+            ├── port_prbs_monitor.sh       # 100G uplink PRBS 測試（bcmcmd phy diag）
+            │                              #   ⚠️ 已納入交付，但 A/B/C 的呼叫仍註解掉（bring-up 中）
+            ├── usb_target.sh              # 偵測 USB 裝置節點／掛載點（排除系統碟）
             ├── bmc_monitor.sh             # BMC 監控：free -m + I2C 寫入/讀回圖樣測試
             ├── bmc_monitor_ddr.sh         # ⚠️ 已停用：B/C 內呼叫處已註解，DDR 壓力改走 bgctl + bmc-manager
             │                              #   ↑ 三支都要 chmod +x 才能跑（見 Key Constraints）
@@ -314,6 +318,8 @@ PROFILE_CHANNELS=( "0:high:8" "1:low:8" ... )   # "channel:operation:change_perc
 | **管理網路 ping** | `mgmt_ping_monitor.sh {start\|stop\|status\|fg\|tail\|clear\|summary}` | 一輪 = 10G leg + 1G leg，各自 `ip address/route replace` 後 `ping -I <if>` 打自己的對端；兩張卡都保持 up。每 leg 記 `ip -s link show` 與該卡的 TX/RX packet delta，另出一行可 grep 的 `RESULT` |
 | **BMC 監控** | `bmc_monitor.sh {start\|stop\|status\|fg\|tail\|clear}` | 由 host 端 `bmc-manager run` 週期取樣 `free -m`，另加一組 **I2C 寫入/讀回圖樣測試**（bus 1、addr 0x41、offset 0x00C0，寫 `55AA55AA` 讀回、再寫 `AA55AA55` 讀回）。B 啟動、C 停止並 `cat log/bmc_poll.log` |
 | **BMC DDR 壓力** | `bmc_monitor_ddr.sh` | ⚠️ **已停用** —— B/C 內呼叫處已註解，改由 `bgctl run bmc-manager run memtester` 取代。檔案保留未刪 |
+| **100G PRBS** | `port_prbs_monitor.sh {start [both\|a\|b]\|stop\|status\|report\|clear}` | 兩個 uplink 各一個 worker，可同時或單獨跑。setup（`lpmode off` → `prbs set` → `prbsstat STArt`）→ 週期 `prbs get`（判定）+ `prbsstat Ber`（只記錄）→ teardown（`STOp` + `prbs clear`）。輸出含 `PRBS OK!` 才算 PASS。**⚠️ A/B/C 的呼叫目前註解掉** |
+| **USB 目標偵測** | `usb_target.sh [-o dev\|mnt\|both\|id] [-n] [-r sec]` | 找出插入的 USB 儲存裝置，排除 `/` 與 `/host` 的底層碟（本平台可能從 USB DOM 開機），多顆時拒絕猜；掛載時會驗證真的可寫 |
 | **打包交付** | `publish/publish.sh [-v Ver] [-f] [-z] [-n]` | 版號讀 Script A 檔頭，複製成 `publish/Script_ABC_Blanton_<Ver>/`，排除 `*.log`，可另出 zip |
 
 ---
@@ -330,7 +336,7 @@ Script A ── logopen Logs/Blanton_Margin_<ts>.log ──┐  (之後所有畫
     │                                              │
     ├─ 登入 admin → sudo -i → root@sonic:~#         │
     ├─ date -s "<host 時間>"   ← 讓 DUT 時戳可對照
-    ├─ rm /host/hw-eval/current/jobs/*   ← 清掉上一輪的 job log
+    ├─ rm /host/hw-eval/jobs/*   ← 清掉上一輪的 job log
     ├─ hw-test-session start / log / status
     ├─ 風扇：max31790 unbind→sleep→bind（18-0020 與 25-0020 各一次）
     │        → fan-speed-control.sh <FAN_SPEED> → 回答 y 確認   │
@@ -374,7 +380,8 @@ Script C
     ├─ nvme smart-log / smartctl -x /dev/nvme0
     ├─ traffic: stop → report   ← per-pair TX/RX 交叉比對，PASS/FAIL/NA（exit 2 = 有 FAIL/NA）
     ├─ show reboot-cause / show uptime  ← soak 期間有沒有意外重開，一眼看得到
-    ├─ cp -r /host/hw-eval/current/jobs/ /mnt/usb/jobs-<YYYYmmdd>_<HHMM>
+    ├─ usb_target.sh -o dev → sync → mount <dev> /mnt/usb
+    ├─ cp bmc_poll.log / mgmt_ping.log → jobs/，再 cp -r jobs/ /mnt/usb/jobs-<YYYYmmdd>_<HHMM>
     └─ hw-test-session finish
     ▼
 [messagebox "GOOD JOB! Test Case DONE"] → 人工檢查 log
@@ -717,14 +724,17 @@ margin status、全部 VRM 軌的 Vin/Vout/Iout/Temp、CB + ICB 溫感讀值，
 - **`bmc_monitor_ddr.sh` 已停用**：B/C 內的呼叫已註解，DDR 壓力改由 `bgctl run bmc-manager run memtester`
   取代。檔案還留在 repo，待確認不再需要後刪除，或在檔頭標註停用。
   （`bmc_monitor.sh` 已於 2026-08-25 重新啟用，並加上 I2C 寫入/讀回圖樣測試。）
-- **`rm /host/hw-eval/current/jobs/*` 清不掉子目錄**：Script A 用的是不帶 `-r` 的 `rm`，但 Script C
+- **`rm /host/hw-eval/jobs/*` 清不掉子目錄**：Script A 用的是不帶 `-r` 的 `rm`，但 Script C
   是 `cp -r` 那個目錄，代表裡面可能有子目錄。清不乾淨的話，上一輪的 job log 會被當成這輪的一起
   複製到 USB。要確認 `bgctl` 的產出結構，必要時改成 `rm -rf .../jobs/*`。
+- **100G PRBS 尚未接進 A/B/C**：`port_prbs_monitor.sh` 已隨包交付、可手動執行，但三支腳本裡的呼叫
+  都還註解著（bring-up 中）。要啟用時記得 PRBS 期間 link 會顯示 down，`stop` 之後才會回來。
+- **Script C 的 USB 掛載走 `mount` 而非 `usb_target.sh -o mnt`**：目前是 `-o dev` 取節點再自己
+  `mount <dev> /mnt/usb`，繞過了工具內建的 `mkdir -p`、exfat/ntfs `modprobe` 與可寫性驗證。
+  掛載點不存在、檔案系統模組沒載、或媒體唯讀時只會失敗一行，job log 就沒帶出來。
 - **風扇確認提示是無限等待**：`wait "Set all configured fan channels to"` 之後才 `sendln "y"`；
   若該版 `fan-speed-control.sh` 不再詢問（或字串改了），這個 `wait` 會永遠等下去，Script A 停在那裡
   且不報錯。加個 `timeout` + 分支會比較保險（記得還原 `timeout = 0`）。
-- **USB 掛載點未檢查**：Script C 直接 `cp -r ... /mnt/usb/`，`/mnt/usb` 沒掛載時只會失敗一行，
-  整輪測試的 job log 就沒被帶出來。可在複製前先 `mountpoint -q /mnt/usb` 判斷。
 - **Script C 沒有倒出 `mgmt_ping.log`**：C 會 `stop` 管理網路監控並印 `ip -s link show`，
   但沒有 `cat ~/Blanton_Script/log/mgmt_ping.log`，所以整個 soak 期間累積的 per-leg `RESULT`
   留在 DUT 上、沒進 master log。Script A 那輪基線有 `cat`。
diff --git a/CLAUDE.md b/CLAUDE.md
index 989c861..a35a63b 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -9,11 +9,12 @@ DUT 端的取數能力由一組 **bash 工具庫** 提供（CB FPGA `pcimem` →
 
 完整架構見 [ARCHITECTURE.md](ARCHITECTURE.md)。
 
-**目前狀態（2026-08-25）**：Script A 為 **V1.0.7**（A 集中記錄 A/B/C 三支的變更）。涵蓋
+**目前狀態（2026-08-26）**：Script A 為 **V1.0.9**（A 集中記錄 A/B/C 三支的變更）。涵蓋
 PCIe AER / DDR EDAC / PMON+TPM / 電壓 margin（9 顆 LTC2980）/ SWB loopback 線速流量 /
 10G+1G 管理網路 ping / BMC DDR 與 USB / NVMe 健康，壓力層走平台的 `bgctl`。
 switch unit 數量由 `config.ttl` 的 `SWB_UNIT0` / `SWB_UNIT1` 宣告，風扇轉速由 `FAN_SPEED` 指定。
-測試 job log 收在 DUT 的 `/host/hw-eval/current/jobs/`，Script C 結束時帶時戳複製到 `/mnt/usb/`。
+測試 job log 收在 DUT 的 `/host/hw-eval/jobs/`，Script C 結束時掛好 USB 再帶時戳複製到 `/mnt/usb/`。
+100G PRBS（`port_prbs_monitor.sh`）已隨包交付，但 **A/B/C 的呼叫仍註解掉**，還在 bring-up。
 最後一次發布是 **V1.0.5**；SWB 的 I2C 通道與位址已於 2026-08-19 上機驗證。
 交付用 `./publish/publish.sh` 打包。
 
@@ -88,6 +89,18 @@ chmod +x ~/Blanton_Script/*.sh               # 佈署後必做一次
 #   bmc_monitor.sh   start/stop         # free -m + BMC I2C 寫入/讀回圖樣測試，log/bmc_poll.log
 #   ⚠️ bmc_monitor_ddr.sh 已停用（DDR 壓力改走 bgctl + bmc-manager），檔案仍在
 
+# ── 100G PRBS（目前 TTL 未啟用，手動測用）────────────
+bash ~/Blanton_Script/port_prbs_monitor.sh start        # 兩個 port 同時
+bash ~/Blanton_Script/port_prbs_monitor.sh start a      # 只跑 Ethernet513
+bash ~/Blanton_Script/port_prbs_monitor.sh start b      # 只跑 Ethernet514
+bash ~/Blanton_Script/port_prbs_monitor.sh report       # PASS/FAIL 統計（沒跑的顯示 SKIP）
+bash ~/Blanton_Script/port_prbs_monitor.sh stop         # 收尾會跑 prbsstat STOp + prbs clear
+#   ⚠️ PRBS 打起來時 link 會顯示 down，這是正常的 —— 所以 start 刻意不印 port status
+
+# ── USB 目標偵測 ────────────────────────────────────
+bash ~/Blanton_Script/usb_target.sh -o dev              # /dev/sdX1
+bash ~/Blanton_Script/usb_target.sh -o mnt              # 掛好並回傳掛載點
+
 # ── 背景壓力（平台工具）──────────────────────────────
 bgctl run /usr/sbin/memtester 1G 100
 bgctl list
@@ -187,6 +200,8 @@ Tera Term 連 COM port (115200-8-N-1)
 - ⚠️ **兩張管理網卡同網段會 ARP flux**：`mgmt_ping_monitor.sh` 讓 eth0/eth1 同時 up，同一個 /24 下
   對端 ARP 可能由任一張卡回應，回包落在沒送封包的那張。`ARP_STRICT=1` 擋掉；判讀時看 `RESULT` 行的
   `nic_tx`/`nic_rx`（該卡自己的 packet delta）—— **ping 成功但 `nic_tx` 接近 0 = 封包從另一張卡出去的**
+- ⚠️ **PRBS 跑起來時 `show interfaces status` 會顯示 DOWN**，那是 link 離開正常運作模式，不是故障。
+  `port_prbs_monitor.sh` 的 `start` 因此刻意不印 port status（避免測試員誤判），只在 `prbs clear` 之後的報表裡印
 - ⚠️ **`ip -s link` 的欄位順序是 `bytes packets errors ...`**，要 packet 數取的是**第 2 欄**不是第 1 欄
 - ⚠️ **`mgmt_ping_monitor.sh` / `bmc_monitor*.sh` 需要 exec bit**，且**不是改用 `bash x.sh start` 就能繞過** ——
   `do_start` 內部是 `setsid "$SCRIPT_PATH" __daemon`，直接執行該路徑。git 記錄是 `100644`，
diff --git a/docs/release-notes/v1.0.9.md b/docs/release-notes/v1.0.9.md
new file mode 100644
index 0000000..b77f733
--- /dev/null
+++ b/docs/release-notes/v1.0.9.md
@@ -0,0 +1,63 @@
+# v1.0.9 — 100G PRBS testing, and the job logs actually reach the USB stick
+
+## ✨ New features
+
+**100G uplink PRBS test**
+* New `port_prbs_monitor.sh` drives a PRBS test on both 100G uplinks: it clears low-power mode, arms the pattern, then polls `phy diag <phy> prbs get` in the background until stopped. A poll counts as PASS only when the output says `PRBS OK!`; `prbsstat Ber` is captured alongside every poll for the record.
+* `stop` runs `prbsstat STOp` and `prbs clear` on each port before rendering the report, so the test does not leave PRBS armed behind it.
+* `report` gives the tally the bench actually wants:
+
+  ```
+  PORT           POLLS    PASS     FAIL     RESULT
+  Ethernet513    42       42       0        PASS
+  Ethernet514    42       40       2        FAIL
+  ```
+* **One port at a time is a first-class mode.** `start a` or `start b` runs a single uplink, which is how you separate a genuine port fault from the DUT not coping with two PRBS streams at once. A port that was not run reports `SKIP`, not `FAIL`.
+* Every command and its full output — setup, each poll, teardown — goes to that port's raw log.
+
+> ⚠️ The script ships in this build and can be run by hand, but **the calls in Script A, B and C are commented out**: PRBS is still under bring-up on this platform.
+
+**USB target detection**
+* `usb_target.sh` reports an inserted USB device's node, mount point or by-id path. It excludes whatever disk backs `/` and `/host` — this platform can boot from a USB DOM, which also reports as USB — refuses to guess when several USB disks are present, and when mounting, verifies the result is writable rather than trusting that `mount` succeeded.
+* Script B builds the USB stress command from the detected node instead of a hard-coded `/dev/sda1`.
+
+## 🐛 Bug fixes
+
+**The job logs were being written to a path nobody collected**
+* Stress output, the monitors' logs and the USB archive disagreed about where the job directory lives. Everything now uses `/host/hw-eval/jobs/`, so what Script B writes is what Script C copies out.
+
+**Script C copied to a USB that was never mounted**
+* The archive step assumed `/mnt/usb` was ready. Script C now finds the device and mounts it first, so a run's logs leave the DUT instead of being written into an empty mount point.
+
+**`show interfaces status` right after starting PRBS reads as a failure**
+* With PRBS armed the link is out of normal operation and reports DOWN. `port_prbs_monitor.sh` deliberately does not print the port status at `start` — it appears in the report instead, after `prbs clear`, labelled as the recovered state.
+
+## 📦 Downloads
+
+| File | Contents |
+|---|---|
+| `Script_ABC_Blanton_V1.0.9.zip` | The full Tera Term working directory, including `Blanton_Script/` to copy onto the DUT |
+
+**After copying to the DUT:**
+
+```bash
+chmod +x ~/Blanton_Script/*.sh      # see below
+grep -rlU $'\r' ~/Blanton_Script    # expect no output
+```
+
+`mgmt_ping_monitor.sh` and `port_prbs_monitor.sh` launch their workers through `bash`, so those two run without the execute bit. `bmc_monitor.sh` and `usb_target.sh` still need it, and neither git (mode 100644) nor a Windows/USB copy carries it. Without the `chmod`, `start` fails with `Permission denied` and the later `cat` finds nothing: **the section ends up empty and nothing reports an error.**
+
+## ⚠️ Before you run
+
+* **Declare the switch population.** `SWB_UNIT0` / `SWB_UNIT1` in `config.ttl` say which switch units this DUT has; traffic and the readiness gate both follow them.
+* **Set `FAN_SPEED`.** It is applied at the start of every run.
+* **Management connectivity is in use, not preserved.** Both management NICs are up and pinging — drive the run from the serial console.
+* **PRBS is not wired into the macros yet.** Run `port_prbs_monitor.sh` by hand if you want it; uncommenting the calls in A/B/C is not supported in this build.
+* **Two settings persist to `config_db.json`** and survive a reboot: LLDP is left disabled and the 100G uplinks are left configured. Restore them before the DUT moves on.
+
+## 🔗 Links
+
+* [ARCHITECTURE.md](https://etgit.et-wen.com/etwen/Blanton_TTL_Script/src/branch/main/ARCHITECTURE.md) — test flow, data models, constraints
+* [CLAUDE.md](https://etgit.et-wen.com/etwen/Blanton_TTL_Script/src/branch/main/CLAUDE.md) — commands and the bench gotchas
+
+**Full changelog:** [V1.0.8...V1.0.9](https://etgit.et-wen.com/etwen/Blanton_TTL_Script/compare/V1.0.8...V1.0.9)
diff --git a/src/Script_ABC_Blanton/1_Blanton_Script_A.ttl b/src/Script_ABC_Blanton/1_Blanton_Script_A.ttl
index da154ae..86c6a66 100644
--- a/src/Script_ABC_Blanton/1_Blanton_Script_A.ttl
+++ b/src/Script_ABC_Blanton/1_Blanton_Script_A.ttl
@@ -1,7 +1,7 @@
 ; =============================================================================
 ; Script A for Blanton
-; Version : V1.0.8
-; Date    : 2026-08-25
+; Version : V1.0.9
+; Date    : 2026-08-26
 ; Author  : ETWen
 ; =============================================================================
 ; Version History:
@@ -58,6 +58,13 @@
 ;                       ScriptA                                         MGMT ping baseline 45s -> 30s, clear the log afterwards
 ;                       ScriptB                                         Show mgmt_ping status after start
 ;                       ScriptC                                         Show mgmt_ping status before stop, cat the report after
+;   V1.0.9  2026-08-26  Blanton_Script/port_prbs_monitor.sh             Add 100G Port PRBS test
+;                                                                         start [both|a|b] - single port isolates a port fault from
+;                                                                         the DUT not coping with two PRBS streams at once
+;                                                                         !! TTL calls are commented out in A/B/C - still under bring-up
+;                       ScriptA/B/C                                     Job log path /host/hw-eval/current/jobs -> /host/hw-eval/jobs
+;                       ScriptC                                         Mount the USB (usb_target.sh) before copying the job logs
+;                       ScriptC                                         Reorder results: stress logs, then MGMT ping, then 100G status
 ; =============================================================================
 include "config.ttl"
 
@@ -94,7 +101,7 @@ sendln cmd
 
 ;Stress log clear
 wait prompt_sonic_root
-sendln "rm /host/hw-eval/current/jobs/*"
+sendln "rm /host/hw-eval/jobs/*"
 
 ; ========== HW Test Session ==========
 wait prompt_sonic_root
@@ -218,7 +225,6 @@ sendln "~/Blanton_Script/mgmt_ping_monitor.sh clear"
 
 
 ; ========== 100G Port Status ==========
-; Lpmode Disable
 wait prompt_sonic_root
 sendln "sudo sfputil lpmode off Ethernet513"
 wait prompt_sonic_root
@@ -233,6 +239,37 @@ sendln "config save -y"
 wait prompt_sonic_root
 sendln "show interfaces status Ethernet513,Ethernet514"
 
+;=============================================================================================================
+; ========== 100G PRBS ==========
+;wait prompt_sonic_root
+;sendln "~/Blanton_Script/port_prbs_monitor.sh start"
+;wait prompt_sonic_root
+;sendln "sleep 10"
+;wait prompt_sonic_root
+;sendln "~/Blanton_Script/port_prbs_monitor.sh status"
+;wait prompt_sonic_root
+;sendln "~/Blanton_Script/port_prbs_monitor.sh stop"
+;wait prompt_sonic_root
+;sendln "~/Blanton_Script/port_prbs_monitor.sh report"
+;wait prompt_sonic_root
+;sendln "~/Blanton_Script/port_prbs_monitor.sh clear"
+
+; ========== 100G Port Status ==========
+;wait prompt_sonic_root
+;sendln "sudo sfputil lpmode off Ethernet513"
+;wait prompt_sonic_root
+;sendln "sudo sfputil lpmode off Ethernet514"
+;wait prompt_sonic_root
+;sendln "config interface -n asic0 startup  Ethernet513"
+;wait prompt_sonic_root
+;sendln "config interface -n asic1 startup  Ethernet514"
+;wait prompt_sonic_root
+;sendln "config save -y"
+
+;wait prompt_sonic_root
+;sendln "show interfaces status Ethernet513,Ethernet514"
+;=============================================================================================================
+
 ; ========== First Traffic Test ==========
 ; Silent MAC
 wait prompt_sonic_root
diff --git a/src/Script_ABC_Blanton/2_Blanton_Script_B.ttl b/src/Script_ABC_Blanton/2_Blanton_Script_B.ttl
index d059897..cb147ae 100644
--- a/src/Script_ABC_Blanton/2_Blanton_Script_B.ttl
+++ b/src/Script_ABC_Blanton/2_Blanton_Script_B.ttl
@@ -40,7 +40,7 @@ sendln "bgctl run /usr/sbin/memtester 1G"   ; Continue Execture
 
 ; ========== SSD read/write ==========
 wait prompt_sonic_root
-sendln "bgctl run qfx5252-stress-ssd 1G --runtime 3600 --passes 5 --write --force --log /host/hw-eval/current/qfx5252-stress-ssd.log"
+sendln "bgctl run qfx5252-stress-ssd 1G --runtime 3600 --passes 5 --write --force --log /host/hw-eval/jobs/qfx5252-stress-ssd.log"
 
 ; ========== USB read/write ==========
 ; ---- Get USB partition node -> usb_dev ----
@@ -51,7 +51,7 @@ waitregex '<<DEV=([^>]*)>>'
 usb_dev = groupmatchstr1
 
 wait prompt_sonic_root
-sprintf2 cmd "bgctl run qfx5252-stress-usb %s 256M --runtime 60 --passes 1 --write --log /host/hw-eval/qfx5252-stress-usb.log" usb_dev
+sprintf2 cmd "bgctl run qfx5252-stress-usb %s 256M --runtime 60 --passes 1 --write --log /host/hw-eval/jobs/qfx5252-stress-usb.log" usb_dev
 sendln cmd
 
 ;wait prompt_sonic_root
@@ -105,6 +105,12 @@ sendln "./Blanton_Script/mgmt_ping_monitor.sh status"
 wait prompt_sonic_root
 sendln "show interfaces status Ethernet513,Ethernet514"
 
+;=============================================================================================================
+; ========== 100G PRBS ==========
+;wait prompt_sonic_root
+;sendln "~/Blanton_Script/port_prbs_monitor.sh start"
+;=============================================================================================================
+
 
 ; ========== Traffic START ==========
 ; Silent MAC
diff --git a/src/Script_ABC_Blanton/3_Blanton_Script_C.ttl b/src/Script_ABC_Blanton/3_Blanton_Script_C.ttl
index b620a4d..234bdfe 100644
--- a/src/Script_ABC_Blanton/3_Blanton_Script_C.ttl
+++ b/src/Script_ABC_Blanton/3_Blanton_Script_C.ttl
@@ -25,8 +25,23 @@ wait prompt_sonic_root
 sendln "~/Blanton_Script/mgmt_ping_monitor.sh status"
 wait prompt_sonic_root
 sendln "~/Blanton_Script/mgmt_ping_monitor.sh stop"
-wait prompt_sonic_root
-sendln "cat ~/Blanton_Script/log/mgmt_ping.log"
+
+;=============================================================================================================
+; 100G PRBS STOP
+;wait prompt_sonic_root
+;sendln "~/Blanton_Script/port_prbs_monitor.sh stop"
+;wait prompt_sonic_root
+;sendln "sudo sfputil lpmode off Ethernet513"
+;wait prompt_sonic_root
+;sendln "sudo sfputil lpmode off Ethernet514"
+;wait prompt_sonic_root
+;sendln "config interface -n asic0 startup  Ethernet513"
+;wait prompt_sonic_root
+;sendln "config interface -n asic1 startup  Ethernet514"
+;=============================================================================================================
+
+
+
 
 ; ========== TAKE DATA ==========
 include "utils/setup_pmon.ttl"
@@ -64,16 +79,26 @@ sendln "cat ./Blanton_Script/log/bmc_poll.log"
 ;wait prompt_sonic_root
 ;sendln "journalctl -u qfx5252-bmc-usb-net-test.service --no-pager"
 
-; ========== 10G/1G MGMT Test result ==========
-wait prompt_sonic_root
-sendln "ip -s link show eth0"
-wait prompt_sonic_root
-sendln "ip -s link show eth1"
-
 
 ; ========== CHECK Stress results ==========
 wait prompt_sonic_root
 sendln "cat ~/hammer/tools/amd/mlucas_amm_log"
+wait prompt_sonic_root
+sendln "cat /host/hw-eval/jobs/qfx5252-stress-ssd.log"
+wait prompt_sonic_root
+sendln "cat /host/hw-eval/jobs/qfx5252-stress-usb.log"
+
+; ========== 10G/1G MGMT Test result ==========
+wait prompt_sonic_root
+sendln "cat ~/Blanton_Script/log/mgmt_ping.log"
+
+; ========== 100G Port ==========
+wait prompt_sonic_root
+sendln "show interfaces status Ethernet513,Ethernet514"
+;=============================================================================================================
+;wait prompt_sonic_root
+;sendln "cat ~/Blanton_Script/log/port_prbs.log "
+;=============================================================================================================
 
 ; ========== CHECK Traffic counters ==========
 if SWB_UNIT0 = 1 && SWB_UNIT1 = 1 then
@@ -109,17 +134,31 @@ sendln "show reboot-cause"
 wait prompt_sonic_root
 sendln "show uptime"
 
+
+; ---- Get USB partition node -> usb_dev ----
+usb_dev = ''
+wait prompt_sonic_root
+sendln 'D=$(bash ~/Blanton_Script/usb_target.sh -o dev 2>/dev/null); echo "<<D""EV=${D:-NONE}>>"'
+waitregex '<<DEV=([^>]*)>>'
+usb_dev = groupmatchstr1
+
+wait prompt_sonic_root
+sendln "sync"
+wait prompt_sonic_root
+sprintf2 cmd "mount %s /mnt/usb" usb_dev
+sendln cmd
+
 ; ========== Copy Stress Log to USB ==========
 wait prompt_sonic_root
-sendln "cp ./Blanton_Script/log/bmc_poll.log /host/hw-eval/current/jobs/"
+sendln "cp ./Blanton_Script/log/bmc_poll.log /host/hw-eval/jobs/"
 wait prompt_sonic_root
-sendln "cp ./Blanton_Script/log/mgmt_ping.log /host/hw-eval/current/jobs/"
+sendln "cp ./Blanton_Script/log/mgmt_ping.log /host/hw-eval/jobs/"
 
 wait prompt_sonic_root
 getdate ts_date "%Y%m%d"
 gettime ts_time "%H%M"
 sprintf2 usb_dst "/mnt/usb/jobs-%s_%s" ts_date ts_time
-sprintf2 cmd "cp -r /host/hw-eval/current/jobs/ %s" usb_dst
+sprintf2 cmd "cp -r /host/hw-eval/jobs/ %s" usb_dst
 sendln cmd
 
 ; ========== HW Test Session ==========
diff --git a/src/Script_ABC_Blanton/Blanton_Script/port_prbs_monitor.sh b/src/Script_ABC_Blanton/Blanton_Script/port_prbs_monitor.sh
new file mode 100644
index 0000000..3d74be8
--- /dev/null
+++ b/src/Script_ABC_Blanton/Blanton_Script/port_prbs_monitor.sh
@@ -0,0 +1,431 @@
+#!/bin/bash
+###############################################################################
+# port_prbs_monitor.sh
+#
+# Version : V1.0.0
+# Author  : ETWen
+# Date    : 20260826
+#
+# Purpose : Run a PRBS test on the two 100G uplinks AT THE SAME TIME and keep
+#           polling until stopped. Each port gets its own background worker:
+#
+#               setup : sfputil lpmode off <port>
+#                       phy diag <phy> prbs set <poly>
+#                       phy diag <phy> prbsstat STArt Interval=<n>
+#               poll  : phy diag <phy> prbs get        <- PASS/FAIL comes from here
+#                       phydiag  <phy> prbsstat Ber    <- recorded only
+#               stop  : phydiag <phy> prbsstat STOp
+#                       phydiag <phy> prbs clear
+#
+#           Every command and its full output goes to that port's raw log.
+#           `stop` tears the test down and renders the report; `report`
+#           prints the PASS/FAIL tally per port.
+#
+# Notes   : - A poll counts as PASS only when the output contains "PRBS OK!".
+#             bcmcmd exits 0 even when the BCM shell rejects a command, so the
+#             exit status cannot be used -- only the output can.
+#           - bcmcmd is always run with </dev/null. Without it, it inherits the
+#             polling loop's stdin and eats it, and the loop runs once.
+#
+# Version History
+# V1.0.0     20260826    Initial Version
+###############################################################################
+
+set -u
+
+###############################################################################
+# User Configurable Section  -- normally this is the only part you need to edit
+###############################################################################
+
+# --- port A ---
+PORT_A_NAME="Ethernet513"
+PORT_A_UNIT=0                  # bcmcmd -n <unit>
+PORT_A_PHY=268                 # phy diag <phy>
+
+# --- port B ---
+PORT_B_NAME="Ethernet514"
+PORT_B_UNIT=1
+PORT_B_PHY=268
+
+# Which ports `start` runs when no argument is given: both | a | b
+# Override per run:  start a   /   start b   /   start both
+# Running one at a time is how you tell a genuine port fault from the DUT not
+# coping with two PRBS streams at once.
+PORTS="both"
+
+# --- PRBS ---
+PRBS_POLY="p=3"                # passed to "prbs set"
+PRBS_STAT_INTERVAL=5           # passed to "prbsstat STArt Interval="
+POLL_INTERVAL_SEC=10           # seconds between polls
+PASS_PATTERN="PRBS OK!"        # a poll is PASS only if the output contains this
+
+# Seconds to wait after the setup commands before the first poll, so the link
+# has settled and the counters mean something.
+SETTLE_SEC=10
+
+
+# Stop after this many polls per port. 0 = run until stopped manually.
+MAX_POLLS=0
+
+# How many recent poll blocks the report shows per port.
+TAIL_ENTRIES=20
+
+# Prefix for privileged commands; empty because this already runs as root.
+SUDO=""
+BCMCMD="bcmcmd"
+
+# Logging
+LOG_DIR=""                     # empty = <script directory>/log
+LOG_NAME="port_prbs.log"
+
+# What `start` does with the log left behind by the previous run:
+#   new | archive | append
+START_LOG_MODE="new"
+
+###############################################################################
+# Internal
+###############################################################################
+SCRIPT_NAME="$(basename -- "${BASH_SOURCE[0]}")"
+SCRIPT_DIR="$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")" && pwd)"
+SCRIPT_PATH="${SCRIPT_DIR}/${SCRIPT_NAME}"
+[ -n "${LOG_DIR}" ] || LOG_DIR="${SCRIPT_DIR}/log"
+
+LOG_FILE="${LOG_DIR}/${LOG_NAME}"
+BASE="${LOG_DIR}/${LOG_NAME%.log}"
+PID_FILE="${BASE}.pid"
+STATE_FILE="${BASE}.state"
+RAW_A="${BASE}_${PORT_A_NAME}.raw"
+RAW_B="${BASE}_${PORT_B_NAME}.raw"
+
+ts()  { date '+%Y-%m-%d %H:%M:%S'; }
+
+# port_tally <name> <raw>  ->  "<polls> <pass> <fail> <verdict>"
+# A raw without a "PRBS START" line means the port was not run this session,
+# which is SKIP -- reporting it as FAIL would make a deliberate single-port
+# run look like half the hardware is broken.
+port_tally() {
+    local name="$1" raw="$2" pass fail polls verdict
+    if [ ! -s "${raw}" ] || ! grep -aq "PRBS START ${name}" "${raw}" 2>/dev/null; then
+        printf '0 0 0 SKIP'; return 0
+    fi
+    pass=$(grep -ac "PRBS ${name} poll=[0-9]* PASS" "${raw}" 2>/dev/null); pass=${pass:-0}
+    fail=$(grep -ac "PRBS ${name} poll=[0-9]* FAIL" "${raw}" 2>/dev/null); fail=${fail:-0}
+    polls=$(( pass + fail ))
+    if [ "${polls}" -gt 0 ] && [ "${fail}" -eq 0 ]; then verdict=PASS; else verdict=FAIL; fi
+    printf '%s %s %s %s' "${polls}" "${pass}" "${fail}" "${verdict}"
+}
+die() { printf '[ERROR] %s\n' "$*" >&2; exit 1; }
+
+# bcm <unit> <dsh command> -- output on stdout, never trusts the exit status.
+# </dev/null so it cannot consume the caller's stdin.
+bcm() {
+    local unit="$1" cmd="$2"
+    ${SUDO} "${BCMCMD}" -n "${unit}" -c "dsh -c \"${cmd}\"" </dev/null 2>&1
+}
+
+# run_step <unit> <dsh command>
+# The command and its full output are written to the LOG via stderr, because
+# the worker has stderr pointed at the raw file. Only the output itself goes to
+# stdout, so `out="$(run_step ...)"` captures the output without swallowing the
+# log lines -- writing both to stdout would have put the whole record inside
+# the variable and left the log with nothing but the poll verdicts.
+run_step() {
+    local unit="$1" cmd="$2" out
+    out="$(bcm "${unit}" "${cmd}")"
+    {
+        printf '[%s] CMD  : bcmcmd -n %s -c '\''dsh -c "%s"'\''\n' "$(ts)" "${unit}" "${cmd}"
+        printf '%s\n' "${out}"
+    } >&2
+    printf '%s' "${out}"
+}
+
+# Echo "<pid_a> <pid_b>" and return 0 while at least one worker is alive. A
+# port that was not started this run is recorded as "-", so a single-port run
+# is a first-class case rather than a half-broken two-port one.
+is_running() {
+    local pa pb alive=0
+    [ -f "${PID_FILE}" ] || return 1
+    pa="$(sed -n '1p' "${PID_FILE}" 2>/dev/null)"; pa="${pa:--}"
+    pb="$(sed -n '2p' "${PID_FILE}" 2>/dev/null)"; pb="${pb:--}"
+    [[ "${pa}" =~ ^[0-9]+$ ]] && kill -0 "${pa}" 2>/dev/null && alive=1
+    [[ "${pb}" =~ ^[0-9]+$ ]] && kill -0 "${pb}" 2>/dev/null && alive=1
+    [ "${alive}" -eq 1 ] || return 1
+    printf '%s %s' "${pa}" "${pb}"
+    return 0
+}
+
+###############################################################################
+# Worker  -- one per port, launched by `start`
+###############################################################################
+WORKER_STOP=0
+worker_on_signal() { WORKER_STOP=1; }
+
+# __worker <name> <unit> <phy> <rawfile>
+do_worker() {
+    local name="$1" unit="$2" phy="$3" raw="$4"
+    local n=0 pass=0 fail=0 out
+
+    exec >>"${raw}" 2>&1
+    trap worker_on_signal INT TERM
+
+    printf '#############################################################\n'
+    printf '[%s] PRBS START %s (unit %s, phy %s) poly=%s interval=%ss poll=%ss\n' \
+           "$(ts)" "${name}" "${unit}" "${phy}" "${PRBS_POLY}" \
+           "${PRBS_STAT_INTERVAL}" "${POLL_INTERVAL_SEC}"
+    printf '#############################################################\n'
+
+    # --- setup ---
+    printf '[%s] CMD  : sfputil lpmode off %s\n' "$(ts)" "${name}"
+    ${SUDO} sfputil lpmode off "${name}" </dev/null 2>&1
+    run_step "${unit}" "phy diag ${phy} prbs set ${PRBS_POLY}"                 >/dev/null
+    run_step "${unit}" "phy diag ${phy} prbsstat STArt Interval=${PRBS_STAT_INTERVAL}" >/dev/null
+
+    sleep "${SETTLE_SEC}"
+
+    # --- poll ---
+    while [ "${WORKER_STOP}" -eq 0 ]; do
+        n=$(( n + 1 ))
+        printf -- '---------- %s POLL %d @ %s ----------\n' "${name}" "${n}" "$(ts)"
+
+        out="$(run_step "${unit}" "phy diag ${phy} prbs get")"
+        # Ber is recorded for the log only; it does not decide the verdict.
+        run_step "${unit}" "phydiag ${phy} prbsstat Ber" >/dev/null
+
+        if printf '%s' "${out}" | grep -qF "${PASS_PATTERN}"; then
+            pass=$(( pass + 1 ))
+            printf '[%s] PRBS %s poll=%d PASS\n' "$(ts)" "${name}" "${n}"
+        else
+            fail=$(( fail + 1 ))
+            printf '[%s] PRBS %s poll=%d FAIL\n' "$(ts)" "${name}" "${n}"
+        fi
+
+        [ "${MAX_POLLS}" -gt 0 ] && [ "${n}" -ge "${MAX_POLLS}" ] && break
+        [ "${WORKER_STOP}" -eq 0 ] || break
+        sleep "${POLL_INTERVAL_SEC}"
+    done
+
+    # --- teardown ---
+    run_step "${unit}" "phydiag ${phy} prbsstat STOp"  >/dev/null
+    run_step "${unit}" "phydiag ${phy} prbs clear"     >/dev/null
+    printf '[%s] PRBS STOP %s polls=%d PASS=%d FAIL=%d\n' \
+           "$(ts)" "${name}" "${n}" "${pass}" "${fail}"
+}
+
+###############################################################################
+# Report
+###############################################################################
+# render_port <name> <unit> <phy> <raw>
+render_port() {
+    local name="$1" unit="$2" phy="$3" raw="$4"
+    local t polls pass fail verdict
+
+    t="$(port_tally "${name}" "${raw}")"
+    polls="$(printf '%s' "${t}" | awk '{print $1}')"
+    pass="$(printf '%s'  "${t}" | awk '{print $2}')"
+    fail="$(printf '%s'  "${t}" | awk '{print $3}')"
+    verdict="$(printf '%s' "${t}" | awk '{print $4}')"
+
+    if [ "${verdict}" = "SKIP" ]; then
+        printf -- '----- %s (unit %s, phy %s) : not run this session -----\n\n' \
+                  "${name}" "${unit}" "${phy}"
+        printf '[%s] RESULT %-12s polls=%-4s PASS=%-4s FAIL=%-4s %s\n\n' \
+               "$(ts)" "${name}" "${polls}" "${pass}" "${fail}" "${verdict}"
+        return 0
+    fi
+
+    printf -- '----- %s (unit %s, phy %s) : last %s poll blocks -----\n' \
+              "${name}" "${unit}" "${phy}" "${TAIL_ENTRIES}"
+    grep -aE "^-{10} ${name} POLL|PRBS ${name} poll=|prbsstat Ber|^ *[0-9]+ *: " "${raw}" 2>/dev/null \
+        | tail -n $(( TAIL_ENTRIES * 3 ))
+    printf '\n'
+    printf '[%s] RESULT %-12s polls=%-4s PASS=%-4s FAIL=%-4s %s\n\n' \
+           "$(ts)" "${name}" "${polls}" "${pass}" "${fail}" "${verdict}"
+}
+
+write_report() {
+    local started
+    started="$(sed -n '1p' "${STATE_FILE}" 2>/dev/null)"
+    {
+        printf '#############################################################\n'
+        printf '[%s] 100G PRBS report\n' "$(ts)"
+        printf '  started : %s\n' "${started:-unknown}"
+        printf '  stopped : %s\n' "$(ts)"
+        printf '  %s : unit %s, phy %s\n' "${PORT_A_NAME}" "${PORT_A_UNIT}" "${PORT_A_PHY}"
+        printf '  %s : unit %s, phy %s\n' "${PORT_B_NAME}" "${PORT_B_UNIT}" "${PORT_B_PHY}"
+        printf '  poly=%s  prbsstat Interval=%s  poll every %ss\n' \
+               "${PRBS_POLY}" "${PRBS_STAT_INTERVAL}" "${POLL_INTERVAL_SEC}"
+        printf '  a poll is PASS only when the output contains "%s"\n' "${PASS_PATTERN}"
+        printf '#############################################################\n\n'
+
+        render_port "${PORT_A_NAME}" "${PORT_A_UNIT}" "${PORT_A_PHY}" "${RAW_A}"
+        render_port "${PORT_B_NAME}" "${PORT_B_UNIT}" "${PORT_B_PHY}" "${RAW_B}"
+
+        # Taken after prbsstat STOp + prbs clear, so this is the recovered
+        # state. During the test the same command would have reported DOWN.
+        printf -- '--- show interfaces status %s,%s (after prbsstat STOp + prbs clear) ---\n' \
+               "${PORT_A_NAME}" "${PORT_B_NAME}"
+        ${SUDO} show interfaces status "${PORT_A_NAME},${PORT_B_NAME}" </dev/null 2>&1
+    } >> "${LOG_FILE}"
+}
+
+###############################################################################
+# Sub-commands
+###############################################################################
+prepare_log_on_start() {
+    local stamp
+    case "${START_LOG_MODE}" in
+        append) return 0 ;;
+        archive)
+            if [ -s "${LOG_FILE}" ]; then
+                stamp="$(date '+%Y%m%d-%H%M%S')"
+                mv -f "${LOG_FILE}" "${LOG_FILE}.${stamp}" || die "cannot archive ${LOG_FILE}"
+            fi ;;
+        new)
+            [ -f "${LOG_FILE}" ] && { : > "${LOG_FILE}" || die "cannot truncate ${LOG_FILE}"; } ;;
+        *) die "invalid START_LOG_MODE: ${START_LOG_MODE}" ;;
+    esac
+}
+
+# do_start [both|a|b|<port name>]
+do_start() {
+    local which="${1:-${PORTS}}" pids pa="-" pb="-" run_a=0 run_b=0
+
+    case "${which}" in
+        both|BOTH|all)                  run_a=1; run_b=1 ;;
+        a|A|"${PORT_A_NAME}")           run_a=1 ;;
+        b|B|"${PORT_B_NAME}")           run_b=1 ;;
+        *) die "unknown port selector '${which}' (use: both | a | b | ${PORT_A_NAME} | ${PORT_B_NAME})" ;;
+    esac
+
+    pids="$(is_running)" && die "already running (pids=${pids})"
+    command -v "${BCMCMD}" >/dev/null 2>&1 || die "${BCMCMD} not found"
+
+    mkdir -p "${LOG_DIR}" || die "cannot create ${LOG_DIR}"
+    prepare_log_on_start
+    # Only the selected ports are truncated. A raw with no "PRBS START" line is
+    # what the report uses to tell "not run this session" from "ran and failed".
+    [ "${run_a}" -eq 1 ] && : > "${RAW_A}"
+    [ "${run_b}" -eq 1 ] && : > "${RAW_B}"
+    printf '%s\n' "$(ts)" > "${STATE_FILE}"
+
+    # One worker per selected port; with both, they run at the same time.
+    # Invoked through bash so the file does not need the execute bit.
+    if [ "${run_a}" -eq 1 ]; then
+        setsid bash "${SCRIPT_PATH}" __worker \
+               "${PORT_A_NAME}" "${PORT_A_UNIT}" "${PORT_A_PHY}" "${RAW_A}" >/dev/null 2>&1 &
+        pa=$!
+        disown "${pa}" 2>/dev/null
+    fi
+    if [ "${run_b}" -eq 1 ]; then
+        setsid bash "${SCRIPT_PATH}" __worker \
+               "${PORT_B_NAME}" "${PORT_B_UNIT}" "${PORT_B_PHY}" "${RAW_B}" >/dev/null 2>&1 &
+        pb=$!
+        disown "${pb}" 2>/dev/null
+    fi
+    printf '%s\n%s\n' "${pa}" "${pb}" > "${PID_FILE}"
+
+    sleep 1
+    [ "${run_a}" -eq 1 ] && { kill -0 "${pa}" 2>/dev/null || die "${PORT_A_NAME} worker failed, see ${RAW_A}"; }
+    [ "${run_b}" -eq 1 ] && { kill -0 "${pb}" 2>/dev/null || die "${PORT_B_NAME} worker failed, see ${RAW_B}"; }
+    printf 'started (%s pid=%s, %s pid=%s)\nlog: %s\n' \
+           "${PORT_A_NAME}" "${pa}" "${PORT_B_NAME}" "${pb}" "${LOG_FILE}"
+
+    # Deliberately NOT printing "show interfaces status" here. With PRBS armed
+    # the link is out of normal operation and reports DOWN, which reads as a
+    # failure to anyone glancing at the console. The status is shown in the
+    # report instead, once PRBS has been cleared.
+}
+
+do_stop() {
+    local pids pa pb i
+    pids="$(is_running)" || { printf 'not running\n'; rm -f "${PID_FILE}"; return 0; }
+    pa="${pids% *}"; pb="${pids#* }"
+
+    # TERM lets each worker finish its poll and run prbsstat STOp / prbs clear.
+    [[ "${pa}" =~ ^[0-9]+$ ]] && kill -TERM "${pa}" 2>/dev/null
+    [[ "${pb}" =~ ^[0-9]+$ ]] && kill -TERM "${pb}" 2>/dev/null
+    for (( i = 0; i < 120; i++ )); do
+        kill -0 "${pa}" 2>/dev/null || kill -0 "${pb}" 2>/dev/null || break
+        sleep 0.5
+    done
+    if kill -0 "${pa}" 2>/dev/null || kill -0 "${pb}" 2>/dev/null; then
+        printf 'workers did not exit in time, sending SIGKILL (PRBS may be left running)\n' >&2
+        kill -KILL "${pa}" 2>/dev/null
+        kill -KILL "${pb}" 2>/dev/null
+    fi
+
+    write_report
+    rm -f "${PID_FILE}"
+    printf 'stopped\nreport: %s\n' "${LOG_FILE}"
+}
+
+do_report() {
+    local name raw pass fail polls verdict
+    printf '%-14s %-8s %-8s %-8s %s\n' PORT POLLS PASS FAIL RESULT
+    printf '%-14s %-8s %-8s %-8s %s\n' -------------- -------- -------- -------- ------
+    for spec in "${PORT_A_NAME}:${RAW_A}" "${PORT_B_NAME}:${RAW_B}"; do
+        name="${spec%%:*}"; raw="${spec#*:}"
+        set -- $(port_tally "${name}" "${raw}")
+        printf '%-14s %-8s %-8s %-8s %s\n' "${name}" "$1" "$2" "$3" "$4"
+    done
+}
+
+do_status() {
+    local pids
+    if pids="$(is_running)"; then
+        printf 'status : running (%s pid=%s, %s pid=%s)\n' \
+               "${PORT_A_NAME}" "${pids% *}" "${PORT_B_NAME}" "${pids#* }"
+    else
+        printf 'status : stopped\n'
+    fi
+    printf 'log    : %s\n' "${LOG_FILE}"
+    do_report
+}
+
+usage() {
+    cat <<EOF
+Usage: ${SCRIPT_NAME} {start [both|a|b]|stop|status|report|clear}
+
+  start    Set up PRBS and poll in the background. With no argument it runs
+           \$PORTS (currently "${PORTS}"); "a" or "b" runs that port alone,
+           which is how you tell a genuine port fault from the DUT not coping
+           with two PRBS streams at once.
+             start        both ports at the same time
+             start a      ${PORT_A_NAME} only
+             start b      ${PORT_B_NAME} only
+           Port status is NOT shown here: with PRBS armed the link reports
+           DOWN, which looks like a failure. See the report instead.
+  stop     Stop polling, run prbsstat STOp + prbs clear on both ports, and
+           render the report into the log
+  report   Print the PASS/FAIL tally per port
+  status   Show worker pids plus the current tally
+  clear    Remove the log and raw captures (must be stopped first)
+
+Log file : ${LOG_FILE}
+Raw      : ${RAW_A}
+           ${RAW_B}
+
+A poll is PASS only when "phy diag <phy> prbs get" reports "${PASS_PATTERN}".
+prbsstat Ber is captured alongside every poll but does not decide the verdict.
+A port that was not run in this session reports SKIP, not FAIL.
+EOF
+}
+
+###############################################################################
+# Entry point
+###############################################################################
+case "${1:-}" in
+    start)  shift; do_start "${1:-${PORTS}}" ;;
+    stop)   do_stop ;;
+    status) do_status ;;
+    report) do_report ;;
+    clear)
+        is_running >/dev/null && die "still running, stop it first"
+        rm -f "${LOG_FILE}" "${LOG_FILE}".[0-9]* "${RAW_A}" "${RAW_B}" "${STATE_FILE}"
+        printf 'log cleared\n' ;;
+    __worker)
+        shift
+        do_worker "$1" "$2" "$3" "$4" ;;
+    -h|--help|"") usage ;;
+    *) printf '[ERROR] unknown sub-command: %s\n\n' "$1" >&2; usage; exit 1 ;;
+esac