M41T56
READ Mode
In this mode, the master reads the M41T56 slave
after setting the slave address (see Figure 10 and
Figure 11., page 9). Following the WRITE Mode
Control Bit (R/W = 0) and the Acknowledge Bit, the
word address An is written to the on-chip address
pointer. Next the START condition and slave ad-
dress are repeated, followed by the READ Mode
Control Bit (R/W = 1). At this point, the master
transmitter becomes the master receiver. The data
byte which was addressed will be transmitted and
the master receiver will send an Acknowledge Bit
to the slave transmitter. The address pointer is
only incremented on reception of an Acknowledge
Figure 10. Slave Address Location
Bit. The M41T56 slave transmitter will now place
the data byte at address An + 1 on the bus. The
master receiver reads and acknowledges the new
byte and the address pointer is incremented to An
+ 2. This cycle of reading consecutive addresses
will continue until the master receiver sends a
STOP condition to the slave transmitter.
An alternate READ Mode may also be implement-
ed, whereby the master reads the M41T56 slave
without first writing to the (volatile) address point-
er. The first address that is read is the last one
stored in the pointer, see Figure 12., page 10.
R/W
START
SLAVE ADDRESS
A
Figure 11. READ Mode Sequence
11 0100 0
AI00602
BUS ACTIVITY:
MASTER
SDA LINE
S
WORD
ADDRESS (n)
S
BUS ACTIVITY:
SLAVE
ADDRESS
SLAVE
ADDRESS
DATA n
DATA n+1
DATA n+X P
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