M93S66, M93S56, M93S46
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SUMMARY DESCRIPTION
This specification covers a range of 4K, 2K, 1K bit
serial Electrically Erasable Programmable Memory (EEPROM) products (respectively for M93S66,
M93S56, M93S46). In this text, these products are
collectively referred to as M93Sx6.
Figure 2. Logic Diagram
Table 1. Signal Names
The M93Sx6 is accessed through a serial input (D)
and output (Q) us in g the MICROWIRE bus protocol. The memory is divided into 256, 128, 64 x16
bit words (respectively for M93S66, M93S56,
M93S46).
The M93Sx6 is accessed by a set of instructions
which includes Read, W rite, Page Write, Write All
and instructions used to set the memory protection. These are summarized in Table 2 and 3).
A Read Data from Memory (READ) instruction
loads the address of the first word to be read into
an internal address pointer. The data contained at
this address is then clocked out serially. The address pointer is automatically incremented after
the data is output and, if the Chi p S elect Input (S)
is held High, the M93Sx6 can output a sequ ential
stream of data words. In this way, the memory can
be read as a data stream from 16 to 4096 bits (for
the M93S66), or continuously as the address
counter automatically rolls over to 0 0h when the
highest address is reached.
Within the time required by a programming cycle
(t
W
), up to 4 words may be written with help of the
Page Write instruction. the whole memory may
also be erased, or set to a predetermined pattern,
by using the Write All instruction.
Within the memory, a us er defined area may be
protected against further Write instructions. The
size of this area is defined by the content of a Protection Register, located outside of the memory
array. As a final protection step, data may be permanently protected by programm ing a One Time
Programming bit (OT P bit) which l ocks t he Prote ction Register content.
Programming is internal ly 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 16 bits at a
time into one of the word locations of the M93Sx6,
the Page Write instruction writes up to 4 words of
16 bits to sequential locations, assum ing in both
cases that all addresses are outside the Write Protected area. 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.
Figure 3. DIP, SO and TSSOP Connections
Note: 1. See page 26 (onwards) for package dimensions, and how
to identify pin-1.
S Chip Select Input
D Serial Data Input
Q Serial Data Output
C Ser ial Clock
PRE Protection Register Enable
W Write Enable
V
CC
Supply Voltage
V
SS
Ground
AI02020
D
V
CC
M93Sx6
V
SS
C Q
PRE
W
S
V
SS
Q
W
PREC
SV
CC
D
AI02021
M93Sx6
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3
4
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