BL93C46 datasheet(5/12 Pages) BELLING | The BL93C46 provides 1024 bits of serial electrically erasable programmable read only memory

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Shanghai Belling Corp., Ltd

BL93C46

Functional Description

The BL93C46 is accessed via a simple and versatile three-wire serial communication interface. Device

operation is controlled by seven instructions issued by the host processor. A valid instruction starts with a

rising edge of CS and consists of a start bit (logic“1”) followed by the appropriate op code and the desired

memory address location.

READ (READ): The Read (READ) instruction contains the address code for the memory location to be read.

After the instruction and address are decoded, data from the selected memory location is available at the

serial output pin DO. Output data changes are synchronized with the rising edges of serial clock SK. It should

be noted that a dummy bit (logic “0”) precedes the 8- or 16-bit data output string.

ERASE/WRITE (EWEN): To assure data integrity, the part automatically goes into the Erase/Write Disable

(EWDS) state when power is first applied. An Erase/Write Enable(EWEN) instruction must be executed first

before any programming instructions can be carried out. Please note that once in the EWEN state,

programming remains enabled until an EWDS instruction is executed or VCC power is removed from the part.

ERASE (ERASE): The Erase (ERASE) instruction programs all bits in the specified memory location to the

logical “1” state. The self-timed erase cycle starts once the ERASE instruction and address are decoded. The

DO pin outputs the Ready/Busy status of the part if CS is brought high after being kept low for a minimum of

250 ns (TCS). A logic “1” at pin DO indicates that the selected memory location has been erased, and the part

is ready for another instruction.

WRITE (WRITE): The Write (WRITE) instruction contains the 8 or 16 bits of data to be written into the

specified memory location. The self-timed programming cycle, tWP, starts after the last bit of data is received

at serial data input pin DI. The DO pin outputs the Ready/Busy status of the part if CS is brought high after

being kept low for a minimum of 250 ns (TCS). A logic “0” at DO indicates that programming is still in progress.

A logic “1” indicates that the memory location at the specified address has been written with the data pattern

contained in the instruction and the part is ready for further instructions. A

Ready/Busy status cannot be

obtained if the CS is brought high after the end of the selftimed programming cycle, TWP.

ERASE ALL (ERAL): The Erase All (ERAL) instruction programs every bit in the memory array to the logic “1”

state and is primarily used for testing purposes. The DO pin outputs the Ready/Busy status of the part if CS is

BL93C46 Datasheet(PDF) 5 Page - SHANGHAI BELLING CO., LTD.