Cantara/wch
.claude/skills/manufacturers/wch/SKILL.md
WCH (Nanjing Qinheng Microelectronics) MPN encoding patterns, suffix decoding, and handler guidance. Use when working with WCH RISC-V MCUs, USB interface chips, or WCHHandler.
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Last scanned: Apr 16, 2026, 6:05 PM6.1s1 file scanned
SKILL.md
- name:
- wch
- description:
- WCH (Nanjing Qinheng Microelectronics) MPN encoding patterns, suffix decoding, and handler guidance. Use when working with WCH RISC-V MCUs, USB interface chips, or WCHHandler.
WCH (Nanjing Qinheng) Manufacturer Skill
MPN Structure
WCH has two main product categories with different structures:
RISC-V and ARM MCUs (CH32 Series)
CH32[CORE][SERIES][PIN][FLASH][PKG][TEMP]
│ │ │ │ │ │ │
│ │ │ │ │ │ └── Temperature (6=industrial)
│ │ │ │ │ └── Package type (T=LQFP, U=QFN)
│ │ │ │ └── Flash size (4=16KB, 8=64KB, B=128KB, C=256KB)
│ │ │ └── Pin code (C=48, R=64, V=100)
│ │ └── Series (003=entry, 103=standard, 203=enhanced, 30x=high-perf)
│ └── Core (V=RISC-V, F=ARM Cortex-M3)
└── CH32 prefix
USB Interface Chips (CH34x Series)
CH[SERIES][VARIANT]
│ │ │
│ │ └── Package variant (G=SOP-16, C=SOP-16 w/crystal, K=ESSOP-10)
│ └── Series (340=USB-UART, 341=USB-Multi, 9340=Enhanced)
└── CH prefix
Example Decoding
CH32V103C8T6
│ │ │ │││
│ │ │ ││└── Temp 6 (industrial)
│ │ │ │└── Package T (LQFP)
│ │ │ └── Flash 8 (64KB)
│ │ └── Pin C (48-pin)
│ └── Series 103 (QingKe V3A core)
└── Core V (RISC-V)
CH340G
│ │ │
│ │ └── Package G (SOP-16)
│ └── Series 340 (USB to UART)
└── CH prefix
Package Codes
MCU Pin Codes
| Code | Package | Pin Count | |------|---------|-----------| | A | QFN-28 | 28 | | C | LQFP-48 | 48 | | F | TSSOP-20 | 20 | | G | QFN-20 | 20 | | J | SOP-20 | 20 | | K | ESSOP-20 | 20 | | N | SOP-8 | 8 | | R | LQFP-64 | 64 | | U | QFN-20 | 20 | | V | LQFP-100 | 100 | | W | QFN-28 | 28 |
USB Interface Chip Packages
| Suffix | Package | |--------|---------| | G | SOP-16 | | C | SOP-16 (integrated crystal) | | K | ESSOP-10 | | N | SOP-8 | | E | MSOP-10 | | X | ESSOP-10 | | T | SSOP-20 | | A | SOP-28 | | B | SSOP-28 | | S | SOP-28 | | H | SOP-28 | | L | LQFP-48 |
Product Families
RISC-V MCUs (CH32Vxxx)
| Series | Core | Clock | Features | |--------|------|-------|----------| | CH32V003 | QingKe V2A | 48MHz | Entry-level, 2KB SRAM | | CH32V103 | QingKe V3A | 80MHz | Standard, 20KB SRAM | | CH32V203 | QingKe V4B | 144MHz | Enhanced, 64KB SRAM | | CH32V208 | QingKe V4C | 144MHz | Bluetooth LE support | | CH32V303 | QingKe V4F | 144MHz | High-performance | | CH32V305 | QingKe V4F | 144MHz | USB HS, Ethernet | | CH32V307 | QingKe V4F | 144MHz | USB HS, Ethernet, CAN |
ARM Cortex-M3 MCUs (CH32Fxxx)
| Series | Core | Clock | Features | |--------|------|-------|----------| | CH32F103 | Cortex-M3 | 72MHz | STM32F103 compatible | | CH32F203 | Cortex-M3 | 144MHz | Enhanced peripherals |
USB Interface Chips
| Series | Type | Features | |--------|------|----------| | CH340 | USB-UART | Most popular, no crystal needed (CH340C) | | CH341 | USB-Multi | UART/I2C/SPI/Parallel | | CH9340 | USB-UART | Enhanced CH340 | | CH342-CH348 | USB-UART | Various channel counts |
Other Interface Chips
| Series | Type | Features | |--------|------|----------| | CH395 | Ethernet | 10/100M Ethernet controller | | CH9121 | ETH-UART | Ethernet to serial | | CH9141 | BLE-UART | Bluetooth LE module | | CH9143 | BLE-UART | Bluetooth LE module | | CH334 | USB Hub | USB hub controller | | CH224 | USB PD | Power Delivery controller | | CH552/554/559 | 8051 USB | 8051-based USB MCUs |
Flash Size Encoding
| Code | Flash Size | |------|------------| | 4 | 16KB | | 6 | 32KB | | 8 | 64KB | | B | 128KB | | C | 256KB | | D | 384KB | | E | 512KB | | G | 1024KB |
Handler Implementation Notes
MCU Package Code Extraction
// MCU format: CH32V103C8T6
// Position: 01234567890123
// ^-- position 8 is pin code 'C'
char pinCode = mpn.charAt(8);
String packageType = MCU_PACKAGE_CODES.get(pinCode);
// Pin count also at position 8
Integer pinCount = MCU_PIN_COUNTS.get(pinCode);
USB Interface Package Extraction
// CH340G -> G = SOP-16
// Last character is package code
String suffix = mpn.substring(mpn.length() - 1);
String pkg = USB_PACKAGE_CODES.get(suffix);
// CH340 without suffix defaults to SOP-16
if (mpn.matches("^CH(340|341|9340)$")) {
return "SOP-16"; // Default package
}
Core Type Detection
The handler provides getCoreType() for MCUs:
| Series | Core Type | |--------|-----------| | CH32V003 | RISC-V QingKe V2A | | CH32V103 | RISC-V QingKe V3A | | CH32V203/208 | RISC-V QingKe V4B | | CH32V303/305/307 | RISC-V QingKe V4F | | CH32F103/203 | ARM Cortex-M3 | | CH552/554/559 | 8051 Enhanced |
Interface Type Detection
The handler provides getInterfaceType() for interface chips:
| Series | Interface Type | |--------|---------------| | CH340, CH9340 | USB to UART | | CH341 | USB to UART/I2C/SPI/Parallel | | CH348 | USB to 8x UART | | CH395 | Ethernet Controller | | CH9121 | Ethernet to UART | | CH9141/9143 | BLE to UART | | CH334 | USB Hub Controller | | CH224 | USB PD Controller |
Related Files
- Handler:
manufacturers/WCHHandler.java - Component types:
MICROCONTROLLER,IC
CH340 vs CH340C
The CH340C has an integrated crystal oscillator:
- CH340G: Requires external 12MHz crystal
- CH340C: No external crystal needed (recommended for new designs)
Both are SOP-16 package and pin-compatible.
STM32 Compatibility
CH32F103 series is designed as a drop-in replacement for STM32F103:
- Same pinout and package options
- Same peripheral registers
- Lower cost alternative
- Note: Not 100% register-compatible, test thoroughly
Learnings & Edge Cases
- QingKe cores: WCH's proprietary RISC-V core implementations (V2A, V3A, V4B, V4C, V4F)
- CH32V003 popularity: Entry-level RISC-V MCU, extremely low cost (~$0.10)
- CH340 dominance: Most common USB-UART chip in Arduino clones and hobbyist boards
- Position-based extraction: MCU pin code at position 8, flash at position 9
- Flash code reuse: Same encoding as STM32 (8=64KB, B=128KB, C=256KB)
- CH32F vs STM32F: Pin-compatible but register differences exist, verify before migration
- Temperature code: 6 = industrial (-40 to +85C) is standard for all CH32 MCUs
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