S-24CS64A Datasheet, PDF (22/44 Pages) Seiko Instruments Inc – 2-WIRE CMOS SERIAL E2PROM

2-WIRE CMOS SERIAL E²PROM
S-24CS64A
Rev.3.3_00
4. Acknowledge check
The I²C-bus protocol includes an acknowledge check function as a handshake function to prevent a
communication error. This function allows detection of a communication failure during data communication
between the microprocessor and E²PROM. This function is effective to prevent malfunction, so it is
recommended to perform an acknowledge check on the microprocessor side.
5. Built-in power-on-clear circuit
E²PROMs have a built-in power-on-clear circuit that initializes the E²PROM. Unsuccessful initialization
may cause a malfunction. For the power-on-clear circuit to operate normally, the following conditions must
be satisfied for raising the power supply voltage.
5.1 Raising power supply voltage
Raise the power supply voltage, starting at 0.2 V maximum, so that the voltage reaches the power supply
voltage to be used within the time defined by t_RISE as shown in Figure 26.
For example, when the power supply voltage to be used is 5.0 V, t_RISE is 200 ms as shown in Figure 27.
The power supply voltage must be raised within 200 ms.
t_RISE (Max.)
Power supply voltage (V_CC)
V_INIT (Max.)
0.2 V
0 V^*1
t_INIT^*2 (Max.)
*1. 0 V means there is no difference in potential between the VCC pin and
the GND pin of the E²PROM.
*2. t_INIT is the time required to initialize the E²PROM. No instructions are
accepted during this time.
Figure 26 Raising Power Supply Voltage
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Seiko Instruments Inc.