DS7505 Datasheet, PDF (12/14 Pages) Maxim Integrated Products – Digital Thermometer and Thermostat

Digital Thermometer and Thermostat
Copy Data [48h]
0100 1000
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.
Software POR [54h]
0101 0100
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.
A) READ 2 BYTES FROM THE TEMPERATURE, TOS, OR THYST REGISTER (CURRENT POINTER LOCATION)
SCL
SDA S 1 0 0 1 A2 A1 A0 R A D7 D6 D5 D4 D3 D2 D1 D0 A D7 D6 D5 D4 D3 D2 D1 D0 N P
START
ADDRESS BYTE
ACK
(SLAVE)
MS DATA BYTE
(FROM SLAVE)
ACK
(MASTER)
LS DATA BYTE
(FROM SLAVE)
NACK STOP
(MASTER)
B) WRITE TO THE CONFIGURATION REGISTER
SCL
SDA S 1 0 0 1 A2 A1 A0 W A 0 0 0 0 0 0 0 1 A D7 D6 D5 D4 D3 D2 D1 D0 A P
START
ADDRESS BYTE
ACK
(SLAVE)
POINTER BYTE
ACK
(SLAVE)
DATA BYTE
(FROM MASTER)
ACK STOP
(SLAVE)
C) WRITE TO THE TOS OR THYST REGISTER
SCL
SDA S 1 0 0 1 A2 A1 A0 W A 0 0 0 0 0 0 P1 P0 A D7 D6 D5 D4 D3 D2 D1 D0 A D7 D6 D5 D4 D3 D2 D1
AP
START
ADDRESS BYTE
ACK
(SLAVE)
POINTER BYTE
ACK
(SLAVE)
MS DATA BYTE
(FROM MASTER)
ACK
(SLAVE)
LS DATA BYTE
(FROM MASTER)
ACK STOP
(SLAVE)
D) READ SINGLE BYTE (NEW POINTER LOCATION)
SCL
SDA S 1 0 0 1 A2 A1 A0 W A 0 0 0 0 0 0 P1 P0 A S 1 0 0 1 A2 A1 A0 R A D7 D6 D5 D4 D3 D2 D1 D0 N P
START
ADDRESS BYTE
ACK
(SLAVE)
POINTER BYTE
ACK REPEAT
(SLAVE) START
ADDRESS BYTE
E) READ FROM THE CONFIGURATION REGISTER (CURRENT POINTER LOCATION)
SCL
SDA S 1 0 0 1 A2 A1 A0 R A D7 D6 D5 D4 D3 D2 D1 D0 N P
ACK
(SLAVE)
DATA BYTE
(FROM SLAVE)
NACK STOP
(MASTER)
START
ADDRESS BYTE
ACK
(SLAVE)
MS DATA BYTE
(FROM SLAVE)
NACK STOP
(MASTER)
Figure 9. 2-Wire Interface Timing
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