M41T11
8/19
Table 10. AC Characteristics
(TA = –40 to 85 °C; VCC = 2.0V to 5.5V)
Note: 1. Transmitter must internally provide a hold time to bridge the undefined region (300ns max.) of the falling edge of SC L.
Symbol Parameter Min Max Unit
fSCL SCL Clock Frequency 0 100 kHz
tLOW Clock Low Period 4.7 µs
tHIGH Clock High Period 4 µs
tRSDA and SCL Rise Time 1 µs
tFSDA and SCL Fall Time 300 ns
tHD:STA START Condition Hold Time
(after this period the first clock pulse is generated) 4µs
t
SU:STA START Condition Setup Time
(only relevant for a repeated start condition) 4.7 µs
tSU:DAT Data Setup Time 250 ns
tHD:DAT (1) Data Hold Time 0 µs
tSU:STO STOP Condition Setup Time 4.7 µs
tBUF Time the bus must be free before a new transmission can start 4.7 µs
WRITE MODE
In this mode the master transmitter transmits to
the M41T11 slave receiver. Bus protocol is shown
in Figure 10. Following the START condition and
slave address, a logic ’0’ (R/W = 0) is placed on the
bus and indicates to the addressed device that
word addres s A n will foll ow and is t o be writt en t o
the on -chi p address pointer. Th e data word to be
written t o the memory is strobed in next and the in-
ternal address pointer is incremented to the next
memory location within the RAM on the reception
of an acknowledge clock. The M41T11 slave re-
ceiver will send an acknowledge clock to the mas-
ter transmitter after it has received the slave
address and again after it has received the word
address and each data byte (see Figure 9) .
READ MODE
In this mode, the mas ter reads the M41T 11 slave
after setting the slave address (see Figure 11).
Following the write mode control bit (R/W = 0) and
the acknowledge bit, the word address A n is wri t-
ten to the on-chip address pointer. Next the
START condition and slave address 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 ad-
dressed will be transmitted and the master receiv-
er will send an acknowledge bit to the slave
transmitter. The address pointer is only increment-
ed on reception of an acknowledge bit. The
M41 T11 slave transmitter will now place the data
byte at address A n + 1 on the bus. The maste r re-
ceiver reads and ackno wledge s the n ew 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 M41T11 slave
without first w ri tin g to the (vol atile) address poin t-
er. The first address that is read is the last one
stored in the p ointer, see Figure 12.