name: atmel description: Atmel/Microchip AVR MPN encoding patterns, suffix decoding, and handler guidance. Use when working with ATmega, ATtiny, SAM, or other Atmel components.

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)

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

32-bit ARM Microcontrollers

Memory Products

Security/Touch Products

Series Number Encoding

ATmega Series Numbers

The number encodes flash size and sometimes pin count:

ATtiny Series Numbers

Variant Suffixes (Before Hyphen)

Example Variants

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

Temperature Grades

Common Arduino Mappings

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)