Attack NXP P87C528 Microprocessor Flash Memory

Attack NXP P87C528 Microprocessor Flash Memory means the engineer will compromise the whole defending system of NXP P87C528 and get the content from flash and rom memory and then make a perfect cloning.

With none of the security bits programmed the code in the program memory can be verified. If the encryption table is programmed, the code will be encrypted when verified. When only security bit 1 (see below Table ) is programmed.

Program Security Bits

Program Security Bits

MOVC instructions executed from external program memory are disabled from fetching code bytes from the  internal memory, EA is latched on Reset and all further programming of the EPROM is disabled. When security bits 1 and 2 are programmed, in addition to the above, verify mode is disabled.

ROM CODE SUBMISSION FOR 8K ROM DEVICES (P87C528)
When submitting ROM code for the 8k ROM devices, the following must be specified:
1. 8k byte user ROM data
2. 64 byte ROM encryption key
3. ROM security bits.

Security Bit 1: When programmed, this bit has two effects on masked ROM parts:
1. External MOVC is disabled, and
2. EA is latched on Reset.
Security Bit 2: When programmed, this bit inhibits Verify User ROM.

Attack NXP P87C528 Microprocessor Flash Memory

Attack NXP P87C528 Microprocessor Flash Memory

NOTE: Security Bit 2 cannot be enabled unless Security Bit 1 is enabled.
If the ROM Code file does not include the options, the following information must be included with the ROM code. For each of the following, check the appropriate box, and send to Philips along with the code:
Security Bit #1: □ Enabled □ Disabled Security Bit #2: □ Enabled □ Disabled
Encryption: □ No □ Yes If Yes, must send key file.