s-24c32c Seiko Instruments Inc., s-24c32c Datasheet - Page 23

• Manufacturer Part Number: s-24c32c
• Description: 2-wire Serial Eeprom S-24c32c/64c 32k/64k-bit
• Manufacturer: Seiko Instruments Inc.

Rev.2.0
3. Phase adjustment during S-24C32C/64C access
[How to reset S-24C32C/64C]
SDA
SCL
The S-24C32C/64C does not have a pin to reset (the internal circuit). The users cannot forcibly reset it externally. If
the communication to the S-24C32C/64C interrupted, the users need to handle it as you do for software.
In the S-24C32C/64C, users are able to reset the internal circuit by inputting a start condition and a stop condition.
Although the reset signal is input to the master device, the S-24C32C/64C’s internal circuit does not go in reset, but
it does by inputting a stop condition to the S-24C32C/64C. The S-24C32C/64C keeps the same status thus cannot
do the next operation. Especially, this case corresponds to that only the master device is reset when the power
supply voltage drops.
If the power supply voltage restored in this status, input the instruction after resetting (adjusting the phase with the
master device) the S-24C32C/64C. How to reset is shown below.
The S-24C32C/64C is able to be reset by a start and stop instructions. When the S-24C32C/64C is reading data
“0” or is outputting the acknowledgment signal, outputs “0” to the SDA line. In this status, the master device
cannot output an instruction to the SDA line. In this case, terminate the acknowledgment output operation or the
Read operation, and then input a start instruction. Figure 26 shows this procedure.
First, input a start condition. Then transmit 9 clocks (dummy clock) of SCL. During this time, the master device
sets the SDA line to “H”. By this operation, the S-24C32C/64C interrupts the acknowledgment output operation or
data output, so input a start condition
doubly sure, input the stop condition to the S-24C32C/64C. The normal operation is then possible.
*1. After 9 clocks (dummy clock), if the SCL clock continues to being output without inputting a start condition, S-
Remark
_00_H
24C32C/64C may go in the write operation when it receives a stop condition. To prevent this, input a start
condition after 9 clocks (dummy clock).
Condition
Regarding this reset procedure with dummy clock, it is recommended to perform at the system
initialization after applying the power supply voltage.
Start
1
Figure 26 Resetting S-24C32C/64C
*1
2
. When a start condition is input, the S-24C32C/64C is reset. To make
Dummy Clock
Seiko Instruments Inc.
8
9
2-WIRE CMOS SERIAL E
Condition
Start
Condition
S-24C32C/64C
Stop
2
PROM
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