4 Atmel AT24C256C
5294BS–TPM–9/10
Figure 2-2. Atmel AT97SC3204 Block Diagram
ROM
Program
EEPROM
Program
33MHz
LPC
Interface
GPIOGPIO6
AVR
8-bit RISC
CPU
SRAM
EEPROM
Data
CRYPTO
Engine
RNG
Timer
Physical
Security
Circuitry
The TPM includes a hardware random number generator, including a FIPS-approved Pseudo Random Number
Generator that is used for key generation and TCG protocol functions. The RNG is also available to the system to
generate random numbers that may be needed during normal operation.
The chip uses a dynamic internal memory management scheme to store multiple RSA keys. Other than the standard
TCG commands (TPM_FlushSpecific, TPM_Loadkey2), no system intervention is required to manage this internal key
cache.
The TPM is offered to OEM and ODM manufacturers as a turnkey solution, including the firmware integrated on the
chip. In addition, Atmel provides the necessary device driver software for integration into certain operating systems,
along with BIOS drivers. Atmel will also provide manufacturing support software for use by OEMs and ODMs during
initialization and verification of the TPM during board assembly.
Full documentation for TCG primitives can be found in the TCG TPM Main Specification, Parts 1 to 3, on the TCG Web
site located at https://www.trustedcomputinggroup.org. TPM features specific to PC Client platforms are specified in
the “TCG PC Client Specific TPM Interface Specification, Version 1.2”, also available on the TCG web site.
Implementation guidance for 32-bit PC platforms is outlined in the “TCG PC Client Specific Implementation
Specification for Conventional BIOS for TCG Version 1.2”, also available on the TCG web site.
