MCP4331-502ESLASHML datasheet(55/88 Pages) MICROCHIP

55 / 88 page

 2010 Microchip Technology Inc.

DS22242A-page 55

MCP433X/435X

7.5

Write Data

Normal and High Voltage

The Write command is a 16-bit command. The format

of the command is shown in Figure 7-2.

A Write command to a volatile memory location

changes that location after a properly formatted Write

command (16-clock) have been received.

7.5.1

SINGLE WRITE TO VOLATILE

MEMORY

The write operation requires that the CS pin be in the

active state (VILor VIHH). Typically, the CS pin will be in

the inactive state (VIH) and is driven to the active state

(VIL). The 16-bit Write command (command byte and

data byte) is then clocked in on the SCK and SDI pins.

Once all 16 bits have been received, the specified

volatile address is updated. A write will not occur if the

write command isn’t exactly 16 clocks pulses. This

protects against system issues from corrupting the

nonvolatile memory locations.

Figure 6-2 and Figure 6-3 show possible waveforms

for a single write.

FIGURE 7-2:

Write Command – SDI and SDO States.

1111111111111111 Valid Address/Command combination

111111

0 Invalid Address/Command combination (1)

COMMAND BYTE

DATA BYTE

SDI

SDO

Note 1: If an Error Condition occurs (CMDERR = L), all following SDO bits will be low until the CMDERR

condition is cleared (the CS pin is forced to the inactive state).

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