Microchip Technology MCP3421EV Datenbogen

MCP3421

DS22003E-page 18

FIGURE 5-1:

MCP3421 Address Byte.

5.3.2

WRITING A CONFIGURATION BYTE
TO THE DEVICE

When the Master sends an address byte with the R/W
bit low (R/W = 0), the MCP3421 expects one
configuration byte following the address. Any byte sent
after this second byte will be ignored. The user can
change the operating mode of the device by writing the
configuration register bits.

If the device receives a write command with a new
configuration setting, the device immediately begins a
new conversion and updates the conversion data.

FIGURE 5-2:

Timing Diagram For Writing To The MCP3421.

Start bit

Read/Write bit

Address Byte

R/W ACK

Device Code Address Bits

(Note 1)

Address

Acknowledge bit

Address

Note 1:

Specified by the customer and programmed at
the factory. If not specified by the customer,
programmed to ‘

000

’.

Stop Bit by

A2 A1 A0

R/W

ACK by

MCP3421

RDY

C1 C0

O/C

S1 S0 G1 G0

1st Byte:

2nd Byte:

Master

ACK by

MCP3421

MCP3421 Address Byte

Configuration Byte

Start Bit by

Master

with Write command

Note:

– Stop bit can be issued any time during writing.
–

MCP3421 device code is 1101.

– Address Bits A2- A0 = 000 are programmed at factory unless customer requests different codes.

SCL

SDA