w78l812a Winbond Electronics Corp America, w78l812a Datasheet - Page 16

• Manufacturer Part Number: w78l812a
• Description: 8-bit Mcu Series 80c51-based
• Manufacturer: Winbond Electronics Corp America

Notes:
1. All these operations happen in RST = V
2. V
3. The program verify operation follows behind the program operation.
4. This erase operation will erase all the on-chip Flash EPROM cells and the Security bits.
5. The erase verify operation follows behind the erase operation.
6.8
During the programmer operation mode, the Flash EPROM can be programmed and verified
repeatedly. Until the code inside the ROM is confirmed OK, the code can be protected. The protection
of ROM and those operations on it are described below.
The W78L812 has a Special Setting Register, the Security Register, which can not be accessed in
normal mode. The register can only be accessed from the on-chip ROM operation mode. Those bits of
the Security Registers can not be changed once they have been programmed from high to low. They
can only be reset through erase-all operation.
The Security Register is addressed in the Flash EPROM operation mode by address #0FFFFh.
Read
Output Disable
Program
Program Verify
Erase
Erase Verify
Program/
Erase Inhibit
OPERATIONS
CP
= 12.5V, V
Security Bits
EP
= 14.5V, V
CTRL)
P3.0
(A9
X
0
0
0
0
1
1
CTRL)
IH
(A13
P3.1
= V
0
0
0
0
0
0
0
DD
, V
CTRL)
IH
(A14
P3.2
IL
, ALE = V
0
0
0
0
0
0
0
= V
SS
CTRL)
.
P3.3
(OE
IL
0
0
0
0
0
0
0
and PSEN = V
- 16 -
(
P3.6
CE
0
0
0
1
0
1
1
)
(
IH
P3.7
OE
.
0
1
1
0
1
0
1
W78LE812/W78L812A
)
(VPP)
VCP/
VCP
VCP
VEP
VEP
VEP
EA
1
1
(A15… A0)
others: X
Address Data Out
Address
Address Data Out
Address Data Out
P2, P1
A0:0,
X
X
(D7… D0)
Data In
Data In
0FFH
Hi-Z
P0
X
NOTES
@3
@4
@5