SNANDer-Droid-MAX/optimization_report.md

SNANDer CH347 优化报告 (macOS)

环境

• 编程器: CH347F (USB-SPI)
• 系统: macOS (libusb/darwin)
• SPI NOR: W25Q128BV (16MB)
• SPI NAND: W25N01GV (128MB)

优化历程

SPI NOR 写入优化

版本	写入时间	速度	改进
初始	251s	66 KB/s	-
优化1: 包打包+减少unprotect	215s	78 KB/s	14%
优化2: 自适应轮询	78s	215 KB/s	69%
最新 (2026-01-18)	73s	224 KB/s	71%

主要优化点

1. 写入包打包: opcode + 地址 + 256B 数据合并到单次 USB 传输
2. 减少冗余操作: snor_unprotect() 移出写入循环
3. 自适应 WIP 轮询: 渐进延迟减少 USB 往返
4. SR_EPE 错误检测: 写入/擦除错误时打印警告
5. NAND OIP 轮询优化: 添加自适应延迟和 5 秒超时保护
6. SPI 速度可选: -S 参数支持 60M/30M/15M/10M/5M/2M

最新测试结果 (2026-01-18)

SPI NOR: W25Q128BV (16MB)

操作	时间	速度
读取	2s	8 MB/s
擦除	33s	-
写入	73s	224 KB/s
验证	2s	8 MB/s

SPI NAND: W25N01GV (128MB)

操作	时间	速度
读取	115s	1.1 MB/s
擦除	3s	43 MB/s
写入	318s	412 KB/s
验证	115s	1.1 MB/s

用法

# 识别芯片
./build/snander -i

# 全片擦除
./build/snander -e

# 写入并验证
./build/snander -w firmware.bin -v

# 指定 SPI 速度
./build/snander -w firmware.bin -v -S 30M

# 启用写入计时 (NOR)
./build/snander -w firmware.bin -v -t

# NAND 禁用 ECC 模式
./build/snander -w firmware.bin -v -d

性能瓶颈分析

CH347 写入比 T48 慢的原因：

1. 主机侧轮询: 每页写入后需状态轮询 (WIP/OIP)，产生大量 USB 往返
2. USB 传输开销: 每包需确认回包，macOS 调度敏感
3. T48 将写入和轮询下放到设备固件，主机只发送数据块

改进建议

• macOS 上使用 sudo 可避免 LIBUSB_ERROR_ACCESS
• 写入时间主要受页编程等待限制，SPI 时钟主要影响读取速度

---

测试示例

1. 芯片识别 (Chip Probe)

SPI NOR (W25Q128BV)

$ ./build/snander -i
...
Using interface 4 for CH347F
Device revision is 1.2.0
SPI speed set to 60M.
spi device id: ef 40 18 0 0 (40180000)
Detected SPI NOR Flash: W25Q128BV, Flash Size: 16 MB

SPI NAND (W25N01GV)

$ ./build/snander -i
...
Using interface 4 for CH347F
Device revision is 1.2.0
SPI speed set to 60M.
spi device id: ff ef aa 21 0 (efaa2100)
SPI NOR Flash Not Detected!
spi_nand_probe: mfr_id = 0xef, dev_id = 0xaa, dev_id_2 = 0x21
Detected SPI NAND Flash: WINBOND W25N01GV, Flash Size: 128MB, OOB Size: 64B

2. SPI NOR (16MB) 写入并验证

$ ./build/snander -w test_16M.bin -v
...
Detected SPI NOR Flash: W25Q128BV, Flash Size: 16 MB
WRITE:
Write addr = 0x0000000000000000, len = 0x0000000001000000
Written 100% [16777216] of [16777216] bytes      
Elapsed time: 73 seconds
Status: OK
VERIFY:
Read addr = 0x0000000000000000, len = 0x0000000001000000
Read 100% [16777216] of [16777216] bytes      
Elapsed time: 2 seconds
Status: OK

2. SPI NAND (W25N01GV 128MB) 写入并验证

$ ./build/snander -w test_128M.bin -v
...
Detected SPI NAND Flash: WINBOND W25N01GV, Flash Size: 128MB, OOB Size: 64B
WRITE:
Write addr = 0x0000000000000000, len = 0x0000000008000000
Written 100% [134217728] of [134217728] bytes      
Elapsed time: 318 seconds
Status: OK
VERIFY:
Read addr = 0x0000000000000000, len = 0x0000000008000000
Read 100% [134217728] of [134217728] bytes      
Elapsed time: 115 seconds
Status: OK