DS1672 Maxim, DS1672 Datasheet - Page 13

• Manufacturer Part Number: DS1672
• Description: The DS1672 low-voltage serial timekeeping chip incorporates a 32-bit counter and power-monitoring functions
• Manufacturer: Maxim

2) Slave transmitter mode (DS1672 read mode): The first byte is received and handled as in the slave
Figure 6. Data Transfer on I
Figure 7. Data Write: Slave Receiver Mode
with the DS1672 acknowledging each byte received. The register pointer will increment after each
byte is transferred. The master will generate a stop condition to terminate the data write.
receiver mode. However, in this mode, the direction bit will indicate that the transfer direction is
reversed. Serial data is transmitted on SDA by the DS1672 while the serial clock is input on SCL.
START and STOP conditions are recognized as the beginning and end of a serial transfer (Figure 8).
The slave address byte is the first byte received after the START condition is generated by the master.
The slave address byte contains the 7-bit DS1672 address, which is 1101000, followed by the
direction bit (R/W), which for a read is a 1. After receiving and decoding the slave address byte the
DS1672 outputs an acknowledge on the SDA line. The DS1672 then begins to transmit data starting
with the register address pointed to by the register pointer. If the register pointer is not written to
before the initiation of a read mode the first address that is read is the last one stored in the register
pointer. The DS1672 must receive a “not acknowledge” to end a read.
S - START
A - ACKNOWLEDGE
P - STOP
R/W - READ/WRITE OR DIRECTION BIT ADDRESS = D0H
S
<Slave Address>
1101000
SDA
SCL
CONDITION
START
0
A
<Word Address (n)>
XXXXXXXX
MSB
1
2
A
slave address
XXXXXXXX A XXXXXXXX A XXXXXXXX A P
<Data(n)
2
C Serial Bus
6
(X+1 BYTES + ACKNOWLEDGE)
7
DATA TRANSFERRED
direction
R/W
8
bit
13 of 15
<Data(n+1)>
signal from receiver
acknowledgement
ACK
9
1
<Data(n+X)>
2
repeated if more bytes
are transferred
3 - 8
8
signal from receiver
acknowledgement
ACK
9
START CONDITION
STOP CONDITION
REPEATED
OR
DS1672