wch

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

USB Interface Chip Packages

Product Families

RISC-V MCUs (CH32Vxxx)

ARM Cortex-M3 MCUs (CH32Fxxx)

USB Interface Chips

Other Interface Chips

Flash Size Encoding

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:

Interface Type Detection

The handler provides getInterfaceType() for interface chips:

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