Description

M93C46, M93C56, M93C66, M93C76, M93C86

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Doc ID 4997 Rev 12

The M93Cx6 is accessed by a set of instructions, as summarized in Table 4, and in more

detail in Table 5: Instruction set for the M93C46 to Table 7: Instruction set for the M93C76

and M93C86).

A Read Data from Memory (READ) instruction loads the address of the first byte or word to

be read in an internal address register. The data at this address is then clocked out serially.

The address register is automatically incremented after the data is output and, if Chip Select

Input (S) is held High, the M93Cx6 can output a sequential stream of data bytes or words. In

this way, the memory can be read as a data stream from eight to 16384 bits long (in the

case of the M93C86), or continuously (the address counter automatically rolls over to 00h

when the highest address is reached).

Programming is internally self-timed (the external clock signal on Serial Clock (C) may be

stopped or left running after the start of a Write cycle) and does not require an Erase cycle

prior to the Write instruction. The Write instruction writes 8 or 16 bits at a time into one of the

byte or word locations of the M93Cx6. After the start of the programming cycle, a

Busy/Ready signal is available on Serial Data Output (Q) when Chip Select Input (S) is

driven High.

An internal Power-on Data Protection mechanism in the M93Cx6 inhibits the device when

the supply is too low.

Figure 2.

DIP, SO, TSSOP and MLP connections (top view)

1.

See Section 12: Package mechanical data for package dimensions, and how to identify pin-1.

2.

DU = Don’t Use. The DU (do not use) pin does not contribute to the normal operation of the device. It is

reserved for use by STMicroelectronics during test sequences. The pin may be left unconnected or may be

Table 4.

Instruction set for the M93Cx6

Instruction

Description

Data

READ

Read Data from Memory

Byte or Word

WRITE

Write Data to Memory

Byte or Word

WEN

Write Enable

WDS

Write Disable

ERASE

Erase Byte or Word

Byte or Word

ERAL

Erase All Memory

WRAL

Write All Memory with same Data

VSS

Q

ORG

DU

C

SVCC

D

AI01929B

M93Cx6

1

2

3

4

8

7

6

5