P87C52 PHILIPS [NXP Semiconductors], P87C52 Datasheet - Page 20

• Manufacturer Part Number: P87C52
• Description: 80C51 8-bit microcontrollers 16K/32K, 512 OTP, I2C, watchdog timer
• Manufacturer: PHILIPS [NXP Semiconductors]

1. P - programmed. U - unprogrammed.
2. Any other combination of the lock bits is not defined.
Philips Semiconductors
Table 7. Program Lock Bits
NOTES:
1999 Jul 23
PROGRAM LOCK BITS
80C51 8-bit microcontrollers
16K/32K, 512 OTP, I
1
2
3
4
ALE/PROG:
ALE/PROG:
LB1
U
P
P
P
LB2
U
U
P
P
1
0
LB3
U
U
U
P
1,2
4–6 MHz
4–6 MHz
PROTECTION DESCRIPTION
No Program Lock features enabled. (Code verify will still be encrypted by the Encryption Array if programmed.)
MOVC instructions executed from external program memory are disabled from fetching code bytes from
Internal memory, EA is jumped and latched on Reset, and further programming of the EPROM Is disabled.
Same as 2, also verify is disabled.
Same as 3, external execution is disabled. Internal data RAM is not accessible.
1
0
A0–A7
2
A0–A7
C, watchdog timer
1
1
1
1
1
1
Figure 14. Programming Configuration
Figure 16. Program Verification
Figure 15. PROG Waveform
P1
RST
P3.6
P3.7
XTAL2
XTAL1
V
P1
RST
P3.6
P3.7
XTAL2
XTAL1
V
SS
SS
10 s MIN
25 PULSES
87C524/8
87C524/8
20
ALE/PROG
ALE/PROG
P2.0–P2.5
P2.0–P2.5
EA/V
EA/V
PSEN
PSEN
P2.7
P2.6
P3.4
P2.7
P2.6
P3.4
V
V
PP
PP
P0
P0
CC
CC
+5 V
+5 V
100 s+10
PGM DATA
1
1
0
0 ENABLE
0
A8–A13
A14
PGM DATA
+12.75 V
25 100 s PULSES TO GROUND
0
1
0
A8–A13
A14
SU00173
87C524/87C528
SU00172
Product specification
SU00018