Atmel (now Microchip) Manufacturer Skill

MPN Structure

Atmel MPNs follow this general structure:

[FAMILY][SERIES][VARIANT]-[PACKAGE][TEMP]
   │       │        │         │      │
   │       │        │         │      └── Optional temperature grade
   │       │        │         └── Package code (after hyphen)
   │       │        └── Feature variant (P=picopower, A=automotive, etc.)
   │       └── Series number (flash size, pin count encoded)
   └── Product family (ATMEGA, ATTINY, ATSAM, etc.)

Example Decoding

ATMEGA328P-PU
│     │  │  ││
│     │  │  │└── (no temp suffix = commercial)
│     │  │  └── U in PU = standard grade
│     │  └── P = picoPower technology
│     └── 328 = 32KB flash, 8-bit
└── ATMEGA = AVR 8-bit megaAVR family

ATSAM3X8E-AU
│    │ ││  ││
│    │ ││  │└── U = standard grade
│    │ ││  └── A = TQFP package
│    │ │└── E = Ethernet variant
│    │ └── 8 = 512KB flash
│    └── 3X = Cortex-M3 SAM3X series
└── ATSAM = ARM-based SAM family

Package Codes (After Hyphen)

| Code | Package | Description | |------|---------|-------------| | PU | PDIP | Plastic Dual In-line Package (through-hole) | | AU | TQFP | Thin Quad Flat Pack (surface mount) | | MU | QFN/MLF | Quad Flat No-leads / Micro Lead Frame | | SU | SOIC | Small Outline IC | | XU | TSSOP | Thin Shrink Small Outline Package | | TU | QFP | Quad Flat Pack (larger than TQFP) | | CU | WLCSP/UCSP | Wafer Level / Ultra Chip Scale Package | | SS | SSOP | Shrink Small Outline Package |

Package Code Pattern

[PACKAGE_TYPE][GRADE]
      │          │
      │          └── U = Standard, C = Commercial, I = Industrial
      └── P=PDIP, A=TQFP, M=QFN, S=SOIC, X=TSSOP, T=QFP, C=WLCSP

Product Families

8-bit AVR Microcontrollers

| Family | Description | Example | |--------|-------------|---------| | ATmega | Feature-rich 8-bit | ATMEGA328P, ATMEGA2560 | | ATtiny | Small footprint 8-bit | ATTINY85, ATTINY13A | | AT90 | USB/CAN enabled | AT90USB162, AT90CAN128 | | ATxmega | Extended 8/16-bit | ATXMEGA128A1U |

32-bit ARM Microcontrollers

| Family | Core | Example | |--------|------|---------| | ATSAM3 | Cortex-M3 | ATSAM3X8E (Arduino Due) | | ATSAM4 | Cortex-M4 | ATSAM4S16B | | ATSAMD | Cortex-M0+ | ATSAMD21G18A | | ATSAME | Cortex-M7 | ATSAME70Q21 |

Memory Products

| Family | Type | Example | |--------|------|---------| | AT24C | I2C EEPROM | AT24C256-PU (256Kbit) | | AT25 | SPI EEPROM/Flash | AT25SF041 (4Mbit Flash) | | AT45DB | DataFlash | AT45DB321E |

Security/Touch Products

| Family | Type | Example | |--------|------|---------| | ATECC | Crypto Authentication | ATECC608A | | ATSHA | SHA Authentication | ATSHA204A | | AT42QT | QTouch Controller | AT42QT1010 | | ATMXT | maXTouch Controller | ATMXT336S |

Series Number Encoding

ATmega Series Numbers

The number encodes flash size and sometimes pin count:

| Series | Flash | SRAM | EEPROM | Notes | |--------|-------|------|--------|-------| | ATMEGA8 | 8KB | 1KB | 512B | Original | | ATMEGA88 | 8KB | 1KB | 512B | Improved | | ATMEGA168 | 16KB | 1KB | 512B | Pin-compatible with 88 | | ATMEGA328 | 32KB | 2KB | 1KB | Arduino Uno | | ATMEGA1284 | 128KB | 16KB | 4KB | High memory | | ATMEGA2560 | 256KB | 8KB | 4KB | Arduino Mega |

ATtiny Series Numbers

| Series | Flash | Pins | Notes | |--------|-------|------|-------| | ATTINY13 | 1KB | 8 | Smallest | | ATTINY25 | 2KB | 8 | | | ATTINY45 | 4KB | 8 | | | ATTINY85 | 8KB | 8 | Popular small MCU | | ATTINY84 | 8KB | 14 | More I/O | | ATTINY2313 | 2KB | 20 | UART included |

Variant Suffixes (Before Hyphen)

| Suffix | Meaning | |--------|---------| | P | picoPower - Ultra low power modes | | A | Revision A / Automotive grade | | V | Low voltage operation (1.8V-5.5V) | | PA | picoPower + Automotive | | PB | picoPower revision B | | U | USB capable | | L | Low voltage (1.8V-3.6V only) |

Example Variants

ATMEGA328    → Original
ATMEGA328P   → picoPower (lower sleep current)
ATMEGA328PB  → picoPower revision B (more features)
ATMEGA328PA  → Automotive grade picoPower

Temperature Grades

| Grade | Range | Suffix Position | |-------|-------|-----------------| | Commercial | 0°C to +70°C | (no suffix) | | Industrial | -40°C to +85°C | Often implicit | | Automotive | -40°C to +125°C | A in variant or separate |

Common Arduino Mappings

| Arduino Board | MCU | Full MPN | |---------------|-----|----------| | Uno | ATmega328P | ATMEGA328P-PU | | Nano | ATmega328P | ATMEGA328P-AU | | Mega 2560 | ATmega2560 | ATMEGA2560-16AU | | Leonardo | ATmega32U4 | ATMEGA32U4-AU | | Due | ATSAM3X8E | ATSAM3X8E-AU | | Zero | ATSAMD21G18A | ATSAMD21G18A-AU |

Handler Implementation Notes

Package Code Extraction

// Atmel package codes are AFTER the hyphen
// ATMEGA328P-PU → package = "PU"

String[] parts = mpn.split("-");
if (parts.length > 1) {
    String suffix = parts[parts.length - 1];
    return switch (suffix) {
        case "PU" -> "PDIP";
        case "AU" -> "TQFP";
        case "MU" -> "QFN/MLF";
        case "SU" -> "SOIC";
        case "XU" -> "TSSOP";
        case "TU" -> "QFP";
        case "CU" -> "WLCSP";
        default -> suffix;
    };
}

Series Extraction

// Extract family + number, stop at variant letter or hyphen
// ATMEGA328P-PU → series = "ATMEGA328"
// ATTINY85-20PU → series = "ATTINY85"

if (mpn.startsWith("ATMEGA")) {
    // Find end of digits after "ATMEGA"
    int end = "ATMEGA".length();
    while (end < mpn.length() && Character.isDigit(mpn.charAt(end))) {
        end++;
    }
    return mpn.substring(0, end);
}

Pattern Matching

// ATmega: ATMEGA + digits + optional letter variant + optional -package
"^ATMEGA[0-9]+[A-Z]?(?:-[A-Z]{2,4})?$"

// ATtiny: ATTINY + digits + optional variant + optional -package
"^ATTINY[0-9]+[A-Z]?(?:-[A-Z]{2,4})?$"

// SAM: ATSAM + series + variant + -package
"^ATSAM[A-Z0-9]+(?:-[A-Z]{2,4})?$"

Pin Compatibility Groups

28-pin PDIP/TQFP Compatible

ATMEGA8 / ATMEGA88 / ATMEGA168 / ATMEGA328
Direct drop-in replacements (different flash sizes)

8-pin DIP/SOIC Compatible

ATTINY13 / ATTINY25 / ATTINY45 / ATTINY85
Increasing flash sizes, same pinout

44-pin TQFP Compatible

ATMEGA16 / ATMEGA32 / ATMEGA644 / ATMEGA1284

Related Files

Handler: manufacturers/AtmelHandler.java
Component types: MICROCONTROLLER_ATMEL, MCU_ATMEL, MEMORY_ATMEL, TOUCH_ATMEL, CRYPTO_ATMEL
Package registry: PackageCodeRegistry.java (Atmel-specific codes: PU, AU, MU, SU, XU, CU)

Learnings & Edge Cases

Microchip acquisition: Atmel was acquired by Microchip in 2016. New parts may have Microchip branding but same MPN structure
Speed grades: Some parts have speed suffix before package (e.g., ATMEGA328P-20AU = 20MHz max)
PU vs AU: Same chip, different package. PU=DIP for prototyping, AU=TQFP for production
P suffix importance: ATMEGA328 and ATMEGA328P are different! The P version has lower power consumption
Memory in name: ATmega328 has 32KB flash (32), ATtiny85 has 8KB (8), but encoding isn't always consistent

Handler Cleanup Notes (TODO)

AtmelHandler needs the same cleanup as TIHandler (PR #77):

[ ] Replace HashSet with Set.of() in getSupportedTypes()
[ ] Handler doesn't use PackageCodeRegistry - has local switch statement
[ ] Pattern may not handle speed grades like -20AU (20MHz before package)
[ ] Case sensitivity - some methods use mpn.startsWith() without toUpperCase()

Test Notes

When creating AtmelHandlerTest:

Put in no.cantara.electronic.component.lib.handlers package (NOT manufacturers)
Use @BeforeAll with MPNUtils.getManufacturerHandler("ATMEGA328P")
Test categories: ATmega, ATtiny, AT90, XMEGA, SAM, Memory (AT24C, AT25), Touch (AT42QT), Crypto (ATECC, ATSHA)