Datasheet

Philips Semiconductors Product specification
8XC54/58
8XC51FA/FB/FC/80C51FA
8XC51RA+/RB+/RC+/RD+/80C51RA+
80C51 8-bit microcontroller family
8K–64K/256–1K OTP/ROM/ROMless, low voltage (2.7V–5.5V),
low power, high speed (33MHz)
2000 Aug 07
45
Table 9. EPROM Programming Modes
MODE RST PSEN ALE/PROG EA/V
PP
P2.7 P2.6 P3.7 P3.6
Read signature 1 0 1 1 0 0 0 0
Program code data 1 0 0* V
PP
1 0 1 1
Verify code data 1 0 1 1 0 0 1 1
Pgm encryption table 1 0 0* V
PP
1 0 1 0
Pgm security bit 1 1 0 0* V
PP
1 1 1 1
Pgm security bit 2 1 0 0* V
PP
1 1 0 0
Pgm security bit 3 1 0 0* V
PP
0 1 0 1
NOTES:
1. ‘0’ = Valid low for that pin, ‘1’ = valid high for that pin.
2. V
PP
= 12.75V ±0.25V.
3. V
CC
= 5V±10% during programming and verification.
* ALE/PROG
receives 5 programming pulses for code data (also for user array; 5 pulses for encryption or security bits) while V
PP
is held at
12.75V. Each programming pulse is low for 100µs (±10µs) and high for a minimum of 10µs.
Table 10. Program Security Bits for EPROM Devices
PROGRAM LOCK BITS
1, 2
SB1 SB2 SB3 PROTECTION DESCRIPTION
1 U U U No Program Security features enabled. (Code verify will still be encrypted by the Encryption Array if
programmed.)
2 P U 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.
3 P P U Same as 2, also verify is disabled.
4 P P P Same as 3, external execution is disabled.
NOTES:
1. P – programmed. U – unprogrammed.
2. Any other combination of the security bits is not defined.