Rainbow-electronics DS7505 Manual de usuario descargar pdf (Pagina 10)

DS7505

Slave Address: Every slave device on the bus has a

unique 7-bit address that allows the master to access

that device. The DS7505’s 7-bit bus address is 1 0 0 1

, where A

, A

, and A

are user-selectable

through the corresponding input pins. The three

address pins allow up to eight DS7505s to be mul-

tidropped on the same bus.

Address Byte: The control byte is transmitted by the

master and consists of the 7-bit slave address plus a

read/write (R/W) bit (see Figure 7). If the master is

going to read data from the slave device then R/W = 1,

and if the master is going to write data to the slave

device then R/W = 0.

Pointer Byte: The pointer byte is used by the master to

tell the DS7505 which register is going to be accessed

during communication. The six MSBs of the pointer

byte (see Figure 8) are always 0 and the two LSBs cor-

respond to the desired register as shown in Figure 8.

Digital Thermometer and Thermostat

10 ______________________________________________________________________________________

Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0

1 0 0 1 A

R/W

Figure 7. Address Byte

Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0

0 0 0 0 0 0 P1 P0

Figure 8. Pointer Byte

START

CONDITION

SDA

SCL

STOP

CONDITION

ACK (OR NACK)

FROM RECEIVER

Figure 6. Start, Stop, and ACK Signals

1 2 ... 5 6 7 8 9 10 11 12 13 14

Sin comentarios

Rainbow-electronics DS7505 Manual de usuario Pagina 10