p87lpc778 NXP Semiconductors, p87lpc778 Datasheet - Page 68

• Manufacturer Part Number: p87lpc778
• Description: Cmos Single-chip 8-bit 80c51 Microcontroller 128-byte Data Ram, 8 Kb Otp
• Manufacturer: NXP Semiconductors

Philips Semiconductors
9397 750 12378
Product data
8.18.2 Security bits
Table 62:
Table 63:
Unprogrammed value: FFH
Table 64:
When neither of the security bits are programmed, the code in the EPROM can be verified.
When only security bit 1 is programmed, all further programming of the EPROM is disabled. At
that point, only security bit 2 may still be programmed. When both security bits are
programmed, EPROM verify is also disabled.
Table 65:
FOSC[2:0]
0 1 0
0 0 1
0 0 0
Bit
7, 6
5 to 0
SB2
1
1
0
0
Bit
Symbol
Symbol
SB2, SB1
-
FOSC2-FOSC0 oscillator configuration
UCFG2 - EPROM system configuration byte 2 register (address FD01H) bit
allocation
UCFG2 - EPROM system configuration byte 2 register (address FD01H) bit
description
EPROM security bits
SB2
7
SB1
1
0
1
0
Rev. 01 — 31 March 2004
SB1
6
Description
EPROM security bits. See
Reserved for future use.
Oscillator configuration
Low frequency crystal, 20 kHz to 100 kHz.
Medium frequency crystal or resonator, 100 kHz to 4 MHz.
High frequency crystal or resonator, 4 MHz to 20 MHz.
5
-
Protection description
Both security bits unprogrammed. No program security
features enabled. EPROM is programmable and
verifiable.
Only security bit 1 programmed. Further EPROM
programming is disabled. Security bit 2 may still be
programmed.
Only security bit 2 programmed. This combination is
not supported.
Both security bits programmed. All EPROM verification
and programming are disabled.
4
-
CMOS single-chip 8-bit microcontroller
…continued
Table 65
3
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© Koninklijke Philips Electronics N.V. 2004. All rights reserved.
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