DS1077

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COMMAND SET

Data and control information is read from and written to the DS1077 in the format shown in Figure 3. To

After receiving an acknowledge, the bus master provides a command protocol. After receiving this protocol,

the DS1077 will issue an acknowledge, and then the master may send data to the DS1077. If the DS1077 is

to be read, the master must send the command protocol as before, and then issue a repeat START condition

and then the control byte again, this time with the R/W bit set to 1 to allow reading of the data from the

DS1077. The command set for the DS1077 is as follows:

Access DIV [01]

is to be written into the DIV register.

Access MUX [02]

is to be written into the MUX register.

Access BUS [0D]

is to be written into the BUS register.

Write E2 [3F]

If WC = 0 the EEPROM is automatically written to at the end of each command. This is a DEFAULT

condition. In this case the command WRITE E2 is not needed.

If WC = 1, the EEPROM is only written when the WRITE E2 command is issued. On receipt of the WRITE

E2 command the contents of the DIV and MUX registers are written into the EEPROM, thus locking in the

register settings.

EXCEPTION: The bus register is always automatically written to EEPROM after a write, regardless of the

value of WC.

APPLICATION INFORMATION

Power-Supply Decoupling

To achieve best results, decouple the power supply with 0.01µF and 0.1µF high-quality, ceramic, surface-

inductance, which improves performance, and ceramic capacitors tend to have adequate high-frequency

response for decoupling applications.

Current Consumption

The active supply current can be significantly reduced by disabling OUT0 when not required and setting its

prescaler to divide by 8. Likewise, bypassing OUT1’s divider (and using only the prescaler) also

significantly reduces the supply current.