DS7505S MAXIM [Maxim Integrated Products], DS7505S Datasheet - Page 12

• Manufacturer Part Number: DS7505S
• Description: Digital Thermometer and Thermostat
• Manufacturer: MAXIM [Maxim Integrated Products]

Copy Data [48h]
Copies data from all SRAM shadow registers to
EEPROM. It is recommended that a Copy Data com-
mand be performed after writing EEPROM-backed
memory locations to guarantee data integrity in the
event of a power loss. The master sends a START fol-
lowed by an address byte containing the DS7505 bus
address. The R/W bit must be a 0. The DS7505
responds with an ACK. If the next byte is a 0x48, the
DS7505 copies all Shadow RAM locations in EEPROM
memory.
Digital Thermometer and Thermostat
Figure 9. 2-Wire Interface Timing
12
A) READ 2 BYTES FROM THE TEMPERATURE, T
SCL
SDA
B) WRITE TO THE CONFIGURATION REGISTER
SCL
SDA
C) WRITE TO THE T
SCL
SDA
D) READ SINGLE BYTE (NEW POINTER LOCATION)
SCL
SDA
E) READ FROM THE CONFIGURATION REGISTER (CURRENT POINTER LOCATION)
SCL
SDA
______________________________________________________________________________________
START
START
START
START
START
S 1
S 1
S 1
S 1
S 1
0
0
0
0
0
OS
0
ADDRESS BYTE
0
ADDRESS BYTE
0
ADDRESS BYTE
0
ADDRESS BYTE
0
ADDRESS BYTE
OR T
1 A2 A1 A0 R
1 A2 A1 A0 W
1 A2 A1 A0 W
1 A2 A1 A0 W
1 A2 A1 A0 R
HYST
REGISTER
(SLAVE)
(SLAVE)
(SLAVE)
(SLAVE)
(SLAVE)
0100 1000
ACK
ACK
ACK
ACK
ACK
A
A
A
A
A
OS
D7 D6 D5 D4 D3 D2 D1 D0
D7 D6 D5 D4 D3 D2 D1 D0
0
0
0
, OR T
0
0
0
HYST
0
POINTER BYTE
0
0
MS DATA BYTE
MS DATA BYTE
(FROM SLAVE)
POINTER BYTE
POINTER BYTE
(FROM SLAVE)
0
REGISTER (CURRENT POINTER LOCATION)
0
0
0
0
0
0 P1 P0
0
0 P1 P0
0
(SLAVE)
1
(MASTER)
ACK
(MASTER)
(SLAVE)
(SLAVE)
NACK
A
ACK
ACK
ACK
N
A
A
A
REPEAT
START
S
D7 D6 D5 D4 D3 D2 D1 D0
D7 D6 D5 D4 D3 D2 D1 D0
D7 D6 D5 D4 D3 D2 D1 D0
STOP
Software POR [54h]
The master sends a START followed by an address
byte containing the DS7505 bus address. The R/W bit
must be a 0. The DS7505 responds with an ACK. If the
next byte is a 0x54, the DS7505 resets as if power had
been cycled, which stops temperature conversions and
resets all registers to their power-up states. No ACK is
sent by the IC after the POR command is received.
Afterwards, the DS7505 makes a single temperature
conversion or continuous temperature conversions,
depending on the state of the SD bit.
1
P
0
(FROM MASTER)
(FROM MASTER)
MS DATA BYTE
(FROM SLAVE)
LS DATA BYTE
DATA BYTE
ADDRESS BYTE
0
1 A2 A1 A0
(MASTER)
(SLAVE)
(SLAVE)
NACK
R
ACK
ACK
(SLAVE)
N
A
A
ACK
A
D7 D6 D5 D4 D3 D2 D1
STOP
STOP
D7 D6 D5 D4 D3 D2 D1 D0
P
P
(FROM MASTER)
LS DATA BYTE
(FROM SLAVE)
0101 0100
DATA BYTE
(SLAVE)
(MASTER)
ACK
NACK
A
N
STOP
STOP
P
P