
Preliminary W78LE51
Publication Release Date: December 1998
- 11 -
Revision A1
Lock bit
This bit is used to protect the customer's program code in the W78LE51. It may be set after the
programmer finishes the programming and verifies sequence. Once this bit is set to logic 0, both the
MTP ROM data and Special Setting Registers can not be accessed again.
MOVC Inhibit
This bit is used to restrict the accessible region of the MOVC instruction. It can prevent the MOVC
instruction in external program memory from reading the internal program code. When this bit is set
to logic 0, a MOVC instruction in external program memory space will be able to access code only in
the external memory, not in the internal memory. A MOVC instruction in internal program memory
space will always be able to access the ROM data in both internal and external memory. If this bit is
logic 1, there are no restrictions on the MOVC instruction.
Encryption
This bit is used to enable/disable the encryption logic for code protection. Once encryption feature is
enabled, the data presented on port 0 will be encoded via encryption logic. Only whole chip erase will
reset this bit.
P1
P3.0
P3.1
P3.2
P3.3
P3.6
P3.7
X'tal1
X'tal2
P0
EA/Vpp
ALE
RST
PSEN
P2
Vss
A0 to A7
V
CP
V
IL
V
IL
V
IL
V
IL
V
IL
V
IH
V
IH
V
IL
A8 to A15
PGM DATA
V
IH
+5V
Programming Configuration
P1
P3.0
P3.1
P3.2
P3.3
P3.6
P3.7
X'tal1
X'tal2
P0
EA/Vpp
ALE
RST
PSEN
P2
Vss
A0 to A7
V
CP
V
IL
V
IL
V
IL
V
IL
V
IH
V
IH
V
IL
V
IL
A8 to A15
PGM DATA
V
IH
+5V
Programming Verification
V
DD
V
DD
ABSOLUTE MAXIMUM RATINGS
PARAMETER
SYMBOL
MIN.
MAX.
UNIT
DC Power Supply
V
DD
V
SS
V
IN
-0.3
+7.0
V
Input Voltage
V
SS
-0.3
V
DD
+0.3
V
Operating Temperature
T
A
0
70
°
C
°
C
Storage Temperature
T
ST
-55
+150
Note: Exposure to conditions beyond those listed under Absolute Maximum Ratings may adversely affect the life and reliability of the
device.