DS89C420 Dallas Semiconducotr, DS89C420 Datasheet - Page 20

• Manufacturer Part Number: DS89C420
• Description: Ultra-High-Speed Microcontroller
• Manufacturer: Dallas Semiconducotr

INSTRUCTION
Mass Erase
Write Program
Memory
Read Program
Memory
Write
Encryption
Array
Write LB1
Write LB2
Write LB3
Read Lock Bits
Write Option
Control
Register
Erase Option
Control
Register
Read Address
30, 31, 60, FC
Table 5. Parallel Programming Instruction Set
1)
2)
3)
4)
Note 1: P3.2 is pulled low during programming to indicate Busy. P3.2 is pulled high again when programming is completed to indicate Ready.
Note 2: P3.0 is pulled high during programming to indicate an error.
Mass erase requires an active-low
Erase option control register requires an active-low
Byte program requires an active-low
PROG
is weakly pulled to a high internally.
Don’t care
Don’t care
Don’t care
Don’t care
Don’t care
Don’t care
Don’t care
P2.5:0,
ADDR
ADDR
ADDR
ADDR
P1.7:0
Don’t care
Don’t care
Don’t care
Don’t care
Don’t care
DOUT
DOUT
DOUT
PROG
P0.7:0
DIN
DIN
DIN
PROG
pulse width of 828ms.
pulse width of 100 m s max.
PROG P2.6
PL
PL
PL
PL
PL
PL
PL
PL
H
H
H
(4)
(4)
(4)
(1)
(3)
(3)
(3)
(3)
(3)
(3)
(2)
PROG
20 of 59
H
H
H
H
H
L
L
L
L
L
L
pulse width of 828ms.
P2.7
H
H
H
H
H
L
L
L
L
L
L
P3.6
H
H
H
H
L
L
L
L
L
L
L
P3.7
H
H
H
H
H
H
L
L
L
L
L
Mass erase the 16k x 8 program
memory, the security block and the
bank select. The contents of every
memory location is returned to FFh.
Program the 16k program memory.
Verify the 16k program memory.
Program the 64 byte encryption
array.
Program LB1 to logic 0.
Program LB2 and LB1 to 00b.
Program LB3, LB2, and LB1 to
000b.
Verify the lock bits. The lock bits
are at address 40h and the three
LSBs of the DOUT are the logic
value of the lock bits LB3, LB2,
and LB1, respectively.
Program the option control register.
Bit 3 of the DIN represents the
watchdog POR default setting.
Erase the option control register.
This operation disables the watch-
dog reset function on power-up.
30h = Manufacturer ID
31h = Device ID
60h = Device extension
FCh = Verify the option control
register. Bit 3 of the DOUT is the
logic value of the watchdog POR.
OPERATION
DS89C420