80C32 Datasheet, PDF (56/62 Pages) NXP Semiconductors – CMOS single-chip 8-bit microcontrollers

Philips Semiconductors
CMOS single-chip 8-bit microcontrollers
Product specification
80C52/80C54/80C58
Security Bits
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
Table 8) is programmed, 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.
Encryption Array
64 bytes of encryption array are initially unprogrammed (all 1s).
Table 8. Program Security Bits
PROGRAM LOCK BITS^{1, 2}
SB1 SB2 PROTECTION DESCRIPTION
1
U
U No Program Security features enabled.
(Code verify will still be encrypted by the Encryption Array if programmed.)
2
P
U MOVC instructions executed from external program memory are disabled from fetching code bytes from
internal memory, EA is sampled and latched on Reset, and further programming of the EPROM is disabled.
NOTES:
1. P – programmed. U – unprogrammed.
2. Any other combination of the security bits is not defined.
80C52 ROM CODE SUBMISSION
When submitting ROM code for the 80C52, the following must be specified:
1. 8k byte user ROM data
2. 64 byte ROM encryption key
3. ROM security bits.
ADDRESS
0000H to 1FFFH
2000H to 201FH
CONTENT
DATA
KEY
BIT(S)
7:0
7:0
2020H
SEC
0
2020H
SEC
1
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.
COMMENT
User ROM Data
ROM Encryption Key
FFH = no encryption
ROM Security Bit 1
0 = enable security
1 = disable security
ROM Security Bit 2
0 = enable security
1 = disable security
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: V Enabled
V Disabled
Security Bit #2: V Enabled
V Disabled
Encryption:
V No
V Yes If Yes, must send key file.
1996 Aug 16
26