M41T00AUD Datasheet, PDF (13/44 Pages) STMicroelectronics – Serial real-time clock with audio

M41T00AUD
Operation
4.2
Characteristics
Table 3. AC characteristics
Symbol
Parameter⁽¹⁾
Min Typ Max Units
f_SCL SCL clock frequency
0
t_LOW Clock Low period
1.3
t_HIGH Clock High period
600
t_R
SDA and SCL Rise time
t_F
SDA and SCL Fall time
START condition Hold time
t_{HD:STA (after this period the first clock pulse is generated)}
600
START condition Setup time
t_{SU:STA (only relevant for a repeated start condition)}
600
t_SU:DAT(2) Data Setup time
100
t_HD:DAT Data Hold time
0
t_SU:STO STOP condition Setup time
600
Time the bus must be free before a new
t_BUF
transmission can start
1.3
400 kHz
µs
ns
300 ns
300 ns
ns
ns
ns
µs
ns
µs
1. Valid for ambient operating temperature: T_A = 0 to 70°C; V_CC = 3.0 to 3.6V (except where noted).
2. Transmitter must internally provide a hold time to bridge the undefined region (300ns max) of the falling
edge of SCL.
4.3
READ mode
In this mode, the master reads the M41T00AUD slave after setting the slave address (see
Figure 8). Following the WRITE mode control bit (R/W = 0) and the acknowledge bit, the
word (register) address An is written 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 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 bit. The device 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 implemented, whereby the master reads the
M41T00AUD slave without first writing to the (volatile) address pointer. The first address
that is read is the last one stored in the pointer (see Figure 10).
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