M50FLW040B ST Microelectronics, M50FLW040B Datasheet - Page 25

• Manufacturer Part Number: M50FLW040B
• Description: 4 Mbit 3V Supply Firmware Hub / Low Pin Count Flash Memory
• Manufacturer: ST Microelectronics

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Table 16. Lock Register Bit Definitions
Note: 1. Applies to Top Block Lock Register (T_BLOCK_LK) and Top Block [-1] Lock Register (T_MINUS01_LK) to Top Block [-7] Lock Reg-
Table 17. General Purpose Inputs Register Definition
Note: 1. Applies to the General Purpose Inputs Register (GPI-REG).
Firmware Hub/Low Pin Count (FWH/LPC)
General Purpose Input Register
The FWH/LPC General Purpose Input Register
holds the state of the General Purpose Input pins,
GPI0-GPI4. When this register is read, the state of
these pins is returned. This register is read-only.
Writing to it has no effect.
7-3
7-5
Bit
Bit
2
1
0
4
3
2
1
0
ister (T_MINUS07_LK).
Lock-Down
Read-Lock
Write-Lock
Bit Name
Bit Name
GPI4
GPI3
GPI2
GPI1
GPI0
Value
Value
‘1’
‘0’
‘1’
‘0’
‘1’
‘0’
‘1’
‘0’
‘1’
‘0’
‘1’
‘0’
‘1’
‘0’
‘1’
‘0’
Reserved
Bus Read operations in this Block always return 00h.
Bus read operations in this Block return the Memory Array contents. (Default
value).
Changes to the Read-Lock bit and the Write-Lock bit cannot be performed. Once a
‘1’ is written to the Lock-Down bit it cannot be cleared to ‘0’; the bit is always reset
to ‘0’ following a Reset (using RP or INIT) or after power-up.
Read-Lock and Write-Lock can be changed by writing new values to them. (Default
value).
Program and Erase operations in this Block will set an error in the Status Register.
The memory contents will not be changed. (Default value).
Program and Erase operations in this Block are executed and will modify the Block
contents.
Reserved
Input Pin GPI4 is at V
Input Pin GPI4 is at V
Input Pin GPI3 is at V
Input Pin GPI3 is at V
Input Pin GPI2 is at V
Input Pin GPI2 is at V
Input Pin GPI1 is at V
Input Pin GPI1 is at V
Input Pin GPI0 is at V
Input Pin GPI0 is at V
IH
IL
IH
IL
IH
IL
IH
IL
IH
IL
The signals on the FWH/LPC Interface General
Purpose Input pins should remain constant
throughout the whole Bus Read cycle.
Manufacturer Code Register
Reading the Manufacturer Code Register returns
the value 20h, which is the Manufacturer Code for
STMicroelectronics. This register is read-only.
Writing to it has no effect.
Function
Function
M50FLW040A, M50FLW040B
(1)
(1)
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