Datasheet

Description M93C46, M93C56, M93C66, M93C76, M93C86
6/34 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
connected to V
CC
or V
SS
.
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
V
SS
Q
ORG
DUC
SV
CC
D
AI01929B
M93Cx6
1
2
3
4
8
7
6
5