Samsung S5PC100, User Manual

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S5PC100 USER’S MANUAL (REV1.0) CRYPTO ENGINE BLOCK
11.3-5
2.4 PKA (PUBLIC KEY ALGORITHM) ENGINE
PKA supports digital-serial radix-4 Montgomery Multiplication Method which is superior to general modular
multiplication algorithms.
PKA engine's features are summarized as follows:
•
Modular Multiplier Design
•
Supports AHB Slave Interface
•
Mode: AxB Mode, Ax1 Mode
•
Supported Key Size: 2048-bit
•
CryptoRAM Size: 2KB
•
Performance: 1129 clocks
2.5 SECURE JTAG
Secure JTAG is implemented in ACE like other security engines.
Secure JTAG is protection for JTAG port from the mul-user who uses debugger to attack S5PC100 system. To
enable or disable use e-fuse ROM Secure JTAG lock on bit. If the Secure JTAG lock on bit is set to “1”, the long
sequence of password should be entered into the debugger to debug S5PC100. The debugging levels are
decided by the e-fuse ROM Secure Access Type bit. Set this bit to ‘0’ to debug the all region include secure part.
Table 11.3- 1 Secure JTAG Debug Mode Selection
Secure Access Type Secure JTAG Lock on Debug Mode
1 0 Non-secure non-protection mode
0 0 Secure non-protection mode
1 1 Non-secure soft lock mode
0 1 Secure soft lock mode
It receives the password sequences through AHB bus from debugger and authenticates the debugger with that
password. If authentication passes, it permits debugger to start debug system. The 80-bit hash value is used for
authentication process.
Figure 11.3-4 shows secure JTAG implementation in S5PC100. Debugger is connected to S5PC100 through
Coresight SubSystem (CSSYS) which provides AHB master operation. Before authentication, debugger can
access only Secure JTAG authentication module in ACE via CSSYS's AHB access port. After authentication,
secure JTAG asserts internal signals so that access controller module drives ARM's authentication input ports
such as DBGEN, NIDEN, SPIDEN and SPNIDEN.