X40010/X40011/X40014/X40015 – Preliminary
– One bit of the slave command byte is a R/W bit. The
R/W bit of the Slave Address Byte deﬁnes the opera-
tion to be performed. When the R/W bit is a one, then
a read operation is selected. A zero selects a write
The word address is either supplied by the master or
obtained from an internal counter. The internal counter
is undeﬁned on a power up condition.
The device powers-up in the following state:
– The device is in the low power standby state.
– The WEL bit is set to ‘0’. In this state it is not possible
to write to the device.
– SDA pin is the input mode.
– RESET/RESET Signal is active for tPURST.
The following circuitry has been included to prevent
– The WEL bit must be set to allow write operations.
– The proper clock count and bit sequence is required
prior to the stop bit in order to start a nonvolatile write
– A three step sequence is required before writing into
the Control Register to change Watchdog Timer or
Block Lock settings.
Figure 14. Sequential Read Sequence
(n is any integer greater than 1)
REV 1.3.4 7/12/02
Characteristics subject to change without notice. 13 of 25