Microchip Technology AT97SC3205T-G3M4C-20

Overview

AT97SC3205T-G3M4C-20 from Microchip Technology (formerly Atmel) is a TCG-compliant Trusted Platform Module (TPM) 1.2 security IC integrating an AVR® RISC microprocessor, hardware asymmetric crypto engine, FIPS-140-2 certified RNG/AES/SHA/RSA engines, and 2066-byte NV user storage. It operates at 3.3V with I²C interface up to 400 kHz and targets secure boot, platform authentication, and key management in embedded systems.

For engineers reviewing the AT97SC3205T-G3M4C-20 datasheet, AT97SC3205T-G3M4C-20 pinout, AT97SC3205T-G3M4C-20 application, or AT97SC3205T-G3M4C-20 equivalent, this page delivers verified package mapping (32-pin QFN), confirmed I²C timing constraints, validated GPIO-Express-00 and PP/GPIO roles, FIPS-140-2 module certification scope, and real-world low-power wake-up behavior using TWI_Wakeup#.

Technical Context

The AT97SC3205T-G3M4C-20 implements the full TCG TPM 1.2 specification in silicon, with dedicated hardware acceleration for RSA key generation and signing, SHA-1 hashing, HMAC-SHA1, and AES encryption. Its internal EEPROM stores RSA keys and supports dynamic key cache management without host intervention.

It uses a dual-voltage I²C interface (SM_DAT/SM_CLK) with configurable pull-up requirements (800 Ω on SM_DAT, 1.5 kΩ on SM_CLK for 400 kHz operation) and includes physical security circuitry, tamper detection via XTAMPER (TestBI/GPIO/XTAMPER), and hardware Physical Presence (PP/GPIO) support for administrative command authorization.

Key Specifications

Pinout & Package

AT97SC3205T-G3M4C-20 is supplied in a 32-pad Very Thin QFN (32M3) package with exposed thermal pad connected to GND. Pinout is defined per Atmel-8883AS-TPM-AT97SC3205T-Datasheet-Summary_022014, Figure 1-1 and Table 1-2.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar TPM 1.2 security module applications.

Compared with SLB9665TT2.0 and NPCT750KB0GX, the AT97SC3205T-G3M4C-20 provides unique GPIO-Express-00 and PP/GPIO pin functionality mapped to specific TPM NV indices and physical presence controls - critical for custom platform attestation workflows requiring hardware-enforced admin consent.

Availability

AT97SC3205T-G3M4C-20 is available at Aetrix Electronics and suitable for server platform integrity, industrial control authentication, embedded device identity, and secure remote attestation requiring stable component supply, long-lifecycle support, and traceable sourcing.

Supply support for AT97SC3205T-G3M4C-20 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Microchip Technology acquired Atmel in 2016 and maintains legacy Atmel security product lines including TPM solutions. The company specializes in microcontrollers, analog, and security ICs for industrial, automotive, and communications markets.

The AT97SC3205T-G3M4C-20 belongs to Atmel's Trusted Platform Module family, designed specifically to deliver TCG-compliant hardware root-of-trust for embedded systems requiring FIPS-validated cryptography and platform attestation capabilities.

FAQ

What is the primary interface type and speed supported by the AT97SC3205T-G3M4C-20?

The AT97SC3205T-G3M4C-20 uses an I²C interface supporting both Standard Mode (100 kHz) and Fast Mode (400 kHz). Stable 400 kHz operation requires SM_DAT pull-up ≤800 Ω and SM_CLK pull-up ≤1.5 kΩ, with clock duty cycle close to 50% for optimal signal integrity. No SPI or LPC interface is implemented in the AT97SC3205T-G3M4C-20.

Does the AT97SC3205T-G3M4C-20 include FIPS-140-2 certification, and what components does it cover?

Yes, the AT97SC3205T-G3M4C-20 is a FIPS-140-2 Level 2 certified module. Certification covers the hardware random number generator (RNG), HMAC, AES, SHA, and RSA cryptographic engines - all implemented in dedicated hardware blocks within the AT97SC3205T-G3M4C-20 die. This certification applies to the complete module, not individual algorithms.

How is the Physical Presence (PP) function implemented on the AT97SC3205T-G3M4C-20?

The AT97SC3205T-G3M4C-20 implements Physical Presence via the PP/GPIO pin (QFN pin 22), which is active-high and features an internal pull-down resistor. When asserted high, it authorizes sensitive administrative commands like TPM_Clear or DictionaryAttackLockReset. The AT97SC3205T-G3M4C-20 requires this pin to be driven externally - no internal auto-assertion occurs.

What is the purpose and behavior of the TWI_Wakeup# pins on the AT97SC3205T-G3M4C-20?

The AT97SC3205T-G3M4C-20 uses two TWI_Wakeup# pins (QFN pins 7 and 22) to recover from low-power deep sleep mode initiated by the TPM_DeepSleep command. Both pins must be pulsed active-low simultaneously to exit sleep - single-pin assertion has no effect. If unused, pin 7 may float or tie to GND; pin 22 must tie to GND or VCC.

Can the AT97SC3205T-G3M4C-20 store user-defined data, and how much space is available?

Yes, the AT97SC3205T-G3M4C-20 provides 2066 bytes of non-volatile (NV) user-defined data storage space, allocated outside the TPM's standard key and PCR structures. This space is accessible via TCG-defined NV write/read commands and persists across power cycles - enabling storage of platform-specific credentials, policy flags, or audit logs without consuming TPM key slots.