Maxim DS87C530 Guía de usuario descargar pdf (Pagina 30)

DS87C530/DS83C530 EPROM/ROM Microcontrollers with Real-Time Clock

30 of 45

Table 9. EPROM Programming Modes

MODE RST

PSEN

ALE/PROG EA/VPP P2.6 P2.7 P3.3 P3.6 P3.7

Program Code Data H L PL 12.75V L H H H H

Verify Code Data H L H H L L L H H

Program Encryption

Array Address 0-3Fh

H L PL 12.75V L H H L H

LB1 H L PL 12.75V H H H H H

LB2 H L PL 12.75V H H H L L

Program Lock

Bits

LB3 H L PL 12.75V H L H H L

Program Option

H L PL 12.75V L H H L L

Read Signature or

Option Registers 30,

31, 60, FCh

H L H H L L L L L

* PL indicates pulse to a logic low.

Table 10. EPROM Lock Bits

LOCK BITS

LEVEL

LB1 LB2 LB3

PROTECTION

1 U U U

No program lock. Encrypted verify if encryption table was

programmed.

2 P U U

Prevent MOVC instructions in external memory from reading

program bytes in internal memory. EA is sampled and latched on

reset. Allow no further programming of EPROM.

3 P P U

Level 2 plus no verify operation. Also, prevent MOVX instructions in

external memory from reading SRAM (MOVX) in internal memory.

4 P P P Level 3 plus no external execution.

1 2 ... 25 26 27 28 29 30 31 32 33 34 35 ... 44 45

Sin comentarios

Maxim DS87C530 Guía de usuario Pagina 30