S-7760A Datasheet, PDF (25/53 Pages) Seiko Instruments Inc – PROGRAMMABLE PORT CONTROLLER (PORT EXPANDER WITH BUILT-IN E2PROM CIRCUIT)

PROGRAMMABLE PORT CONTROLLER (PORT EXPANDER WITH BUILT-IN E²PROM CIRCUIT)
Rev.1.3_00
S-7760A
6. 3 Acknowledgment polling
Acknowledge polling is used to find when the Write operation has completed. After receiving a stop condition the Write
operation has once started, all operations are inhibited to be performed so that the S-7760A cannot respond to the
signals transmitted from the master device. The master device sends a start condition, the device address and
Read/Write instruction code to the S-7760A (slave device), and detects the response from the slave device. It is
possible to find when the Write operation has completed. Thus if the slave device does not send an acknowledgment
signal back, the Write operation is in progress. If it sends an acknowledgment signal back, the Write operation has
completed. Fix the WP pin until an acknowledgment is confirmed. It is recommended to use the Read instruction “1”
for the Read/Write instruction code transmitted from the master device during acknowledgment polling.
6. 4 Irregular action
In the middle of inputting Write data, if inputting a stop condition in clock less than the specified data length (8-bit), the
S-7760A does not perform Write to the E²PROM. And it either does not perform Write to the E²PROM if receiving a
stop condition after receiving data over 9-bit. However, data in the register has been rewritten at the point when the
S-7760A has received the specified length data. Be sure not to input clock which exceeds the specified value due to
noise or other causes.
Seiko Instruments Inc.
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