M50FW040 datasheet(31/53 Pages) STMICROELECTRONICS

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M50FW040

Firmware hub (FWH) interface Configuration Registers

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6.1.3

Lock Down

The Lock Down Bit provides a mechanism for protecting software data from simple hacking

and malicious attack. When the Lock Down Bit is set, ‘1’, further modification to the Write

Lock, Read Lock and Lock Down Bits cannot be performed. A reset or power-up is required

before changes to these bits can be made. When the Lock Down Bit is reset, ‘0’, the Write

Lock, Read Lock and Lock Down Bits can be changed.

6.2

Firmware Hub (FWH) General-Purpose Input Register

The Firmware Hub (FWH) General Purpose Input Register holds the state of the Firmware

Hub Interface General Purpose Input pins, FGPI0-FGPI4. When this register is read, the

state of these pins is returned. This register is read-only and writing to it has no effect.

The signals on the Firmware Hub Interface General Purpose Input pins should remain

constant throughout the whole Bus Read cycle in order to guarantee that the correct data is

read.

6.3

Manufacturer Code Register

Reading the Manufacturer Code Register returns the manufacturer code for the memory.

The manufacturer code for STMicroelectronics is 20h. This register is read-only and writing

to it has no effect.

6.4

Device Code Register

Reading the Device Code Register returns the device code for the memory, 2Ch. This

6.5