DS89C420 Datasheet, PDF (20/59 Pages) Dallas Semiconductor – Ultra-High-Speed Microcontroller

DS89C420
Table 5. Parallel Programming Instruction Set
P2.5:0,
INSTRUCTION
P1.7:0
P0.7:0 PROG P2.6 P2.7 P3.6 P3.7
OPERATION
Mass Erase
Mass erase the 16k x 8 program
Don’t care Don’t care PL⁽¹⁾ H
L
L
L
memory, the security block and the
bank select. The contents of every
memory location is returned to FFh.
Write Program
Memory
ADDR
DIN
PL⁽³⁾ L H H H Program the 16k program memory.
Read Program
Memory
ADDR
DOUT
H⁽⁴⁾
L
L
H H Verify the 16k program memory.
Write
Encryption
Array
ADDR
DIN
PL⁽³⁾ L
H
L
H
Program the 64 byte encryption
array.
Write LB1
Don’t care Don’t care PL⁽³⁾ H H H H Program LB1 to logic 0.
Write LB2
Write LB3
Don’t care Don’t care PL⁽³⁾ H H L L
Don’t care Don’t care PL⁽³⁾ H L H L
Read Lock Bits Don’t care DOUT
H⁽⁴⁾
L
L
L
H
Write Option
Control
Don’t care
DIN
PL⁽³⁾ L H L L
Register
Erase Option
Control
Don’t care Don’t care PL⁽²⁾ H L L H
Register
Read Address
30, 31, 60, FC
ADDR
DOUT
H⁽⁴⁾
L
L
L
L
1) _{Mass erase requires an active-low PROG pulse width of 828ms.}
2) _{Erase option control register requires an active-low PROG pulse width of 828ms.}
3) _{Byte program requires an active-low PROG pulse width of 100ms max.}
4) _{PROG is weakly pulled to a high internally.}
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.
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.
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