Rainbow Electronics DS7505 - Manual (Page 12)

DS7505
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.
Digital Thermometer and Thermostat
12 ______________________________________________________________________________________
SCL
START ADDRESS BYTE
A) READ 2 BYTES FROM THE TEMPERATURE, T
OS
, OR T
HYST
REGISTER (CURRENT POINTER LOCATION)
SDA S 1 0 0 1 A2 A1 A0 R A A N P D7 D6 D5 D4 D3 D2 D1 D0 D7 D6 D5 D4 D3 D2 D1 D0
MS DATA BYTE
(FROM SLAVE)
LS DATA BYTE
(FROM SLAVE)
ACK
(SLAVE)
ACK
(MASTER)
NACK
(MASTER)
STOP
SCL
START ADDRESS BYTE
E) READ FROM THE CONFIGURATION REGISTER (CURRENT POINTER LOCATION)
SDA S 1 0 0 1 A2 A1 A0 R A N P D7 D6 D5 D4 D3 D2 D1 D0
MS DATA BYTE
(FROM SLAVE)
ACK
(SLAVE)
NACK
(MASTER)
STOP
SCL
START ADDRESS BYTE
B) WRITE TO THE CONFIGURATION REGISTER
SDA S 1 0 0 1 A2 A1 A0 W A A A P 0 0 0 0 0 0 0 1 D7 D6 D5 D4 D3 D2 D1 D0
POINTER BYTE DATA BYTE
(FROM MASTER)
ACK
(SLAVE)
ACK
(SLAVE)
ACK
(SLAVE)
STOP
SCL
START ADDRESS BYTE
C) WRITE TO THE T OS OR T HYST REGISTER
SDA S 1 0 0 1 A2 A1 A0 W A A 0 0 0 0 0 0 P1 P0 D7 D6 D5 D4 D3 D2 D1 D0
POINTER BYTE MS DATA BYTE
(FROM MASTER)
ACK
(SLAVE)
ACK
(SLAVE)
A A P D7 D6 D5 D4 D3 D2 D1
LS DATA BYTE
(FROM MASTER)
ACK
(SLAVE)
ACK
(SLAVE)
STOP
SCL
START ADDRESS BYTE
D) READ SINGLE BYTE (NEW POINTER LOCATION)
SDA S 1 0 0 1 A2 A1 A0 W A A S 0 0 0 0 0 0 P1 P0 1 0 0 1 A2 A1 A0
POINTER BYTE ADDRESS BYTE ACK
(SLAVE)
ACK
(SLAVE)
REPEAT
START
R A N P D7 D6 D5 D4 D3 D2 D1 D0
DATA BYTE
(FROM SLAVE)
ACK
(SLAVE)
NACK
(MASTER)
STOP
Figure 9. 2-Wire Interface Timing