M93C86, M93C76, M93C66, M93C56, M93C46
Description
Table 3.
Device
Memory size versus organization
Number of bits
Number of 8-bit bytes
Number of 16-bit words
M93C86
M93C76
M93C66
M93C56
M93C46
16384
8192
4096
2048
1024
2048
1024
512
1024
512
256
128
64
256
128
The M93Cx6 is accessed by a set of instructions, as summarized in Table 4., and in more
detail in Table 5. to Table 7.).
Table 4.
Instruction set for the M93Cx6
Description
Instruction
Data
Byte or Word
READ
WRITE
WEN
Read Data from Memory
Write Data to Memory
Write Enable
Byte or Word
WDS
Write Disable
ERASE
ERAL
Erase Byte or Word
Erase All Memory
Byte or Word
Write All Memory
with same Data
WRAL
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.
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STMICROELECTRONICS [ ST ]
