M93S66-MN6T STMicroelectronics, M93S66-MN6T Datasheet - Page 9

• Manufacturer Part Number: M93S66-MN6T
• Manufacturer: STMicroelectronics

Specifications of M93S66-MN6T

• Density: 4Kb
• Interface Type: Serial (Microwire)
• Organization: 256x16
• Frequency (max): 2MHz
• Write Protection: Yes
• Data Retention: 40Year
• Operating Supply Voltage (typ): 5V
• Package Type: SOIC N
• Operating Temp Range: -40C to 85C
• Supply Current: 2mA
• Operating Supply Voltage (min): 4.5V
• Operating Supply Voltage (max): 5.5V
• Operating Temperature Classification: Industrial
• Mounting: Surface Mount
• Pin Count: 8
• Lead Free Status / Rohs Status: Not Compliant

Read
The Read Data from Memory (READ) instruction
outputs serial data on Serial Data Output (Q).
When the instruction is received, the op-code and
address are decoded, and the data from the mem-
ory is transferred to an output shift register. A dum-
my 0 bit is output first, followed by the 16-bit word,
with the most significant bit first. Output data
changes are triggered by the rising edge of Serial
Clock (C). The M93Sx6 automatically increments
the internal address register and clocks out the
next byte (or word) as long as the Chip Select In-
put (S) is held High. In this case, the dummy 0 bit
is not output between bytes (or words) and a con-
tinuous stream of data can be read.
Write Enable and Write Disable
The Write Enable (WEN) instruction enables the
future execution of write instructions, and the Write
Disable (WDS) instruction disables it. When power
is first applied, the M93Sx6 initializes itself so that
write instructions are disabled. After an Write En-
able (WEN) instruction has been executed, writing
remains enabled until an Write Disable (WDS) in-
struction is executed, or until V
power-on reset threshold voltage. To protect the
memory contents from accidental corruption, it is
advisable to issue the Write Disable (WDS) in-
struction after every write cycle. The Read Data
from Memory (READ) instruction is not affected by
the Write Enable (WEN) or Write Disable (WDS)
instructions.
CC
falls below the
Write
The Write Data to Memory (WRITE) instruction is
composed of the Start bit plus the op-code fol-
lowed by the address and the 16 data bits to be
written.
Write Enable (W) must be held High before and
during the instruction. Input address and data, on
Serial Data Input (D) are sampled on the rising
edge of Serial Clock (C).
After the last data bit has been sampled, the Chip
Select Input (S) must be taken Low before the next
rising edge of Serial Clock (C). If Chip Select Input
(S) is brought Low before or after this specific time
frame, the self-timed programming cycle will not
be started, and the addressed location will not be
programmed.
While the M93Sx6 is performing a write cycle, but
after a delay (t
becomes available, Chip Select Input (S) can be
driven High to monitor the status of the write cycle:
Serial Data Output (Q) is driven Low while the
M93Sx6 is still busy, and High when the cycle is
complete, and the M93Sx6 is ready to receive a
new instruction. The M93Sx6 ignores any data on
the bus while it is busy on a write cycle. Once the
M93Sx6 is Ready, Serial Data Output (Q) is driven
High, and remains in this state until a new start bit
is decoded or the Chip Select Input (S) is brought
Low.
Programming is internally self-timed, so the exter-
nal Serial Clock (C) may be disconnected or left
running after the start of a write cycle.
SLSH
M93S66, M93S56, M93S46
) before the status information
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