MCP4141 MICROCHIP [Microchip Technology], MCP4141 Datasheet - Page 49

• Manufacturer Part Number: MCP4141
• Description: 7/8-Bit Single/Dual SPI Digital POT with Non-Volatile Memory
• Manufacturer: MICROCHIP [Microchip Technology]

7.5
The Write command is a 16-bit command. The Write
Command can be issued to both the Volatile and
Non-Volatile memory locations. The format of the
command is shown in
A Write command to a Volatile memory location
changes that location after a properly formatted Write
Command (16-clock) have been received.
A Write command to a Non-Volatile memory location
will only start a write cycle after a properly formatted
Write Command (16-clock) have been received and the
CS pin transitions to the inactive state (V
7.5.1
The write operation requires that the CS pin be in the
active state (V
the inactive state (V
(V
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
Non-Volatile memory locations.
Figure 6-3
for a single write.
FIGURE 7-2:
© 2008 Microchip Technology Inc.
SDI
SDO
Note:
IL
). The 16-bit Write Command (Command Byte and
Note 1: If an Error Condition occurs (CMDERR = L), all following SDO bits will be low until the CMDERR
D
A
3
1
1
Write Data
Normal and High Voltage
and
Writes to certain memory locations will be
dependant on the state of the WiperLock
Technology bits and the Write Protect bit.
SINGLE WRITE TO VOLATILE
MEMORY
D
A
2
1
1
COMMAND BYTE
IL
condition is cleared (the CS pin is forced to the inactive state).
or V
Figure 6-4
A
D
1
1
1
IHH
IH
A
D
0
1
1
) and is driven to the active state
Figure
Write Command - SDI and SDO States.
). Typically, the CS pin will be in
0
1
1
show possible waveforms
0
1
1
7-2.
D
1
0
9
D
8
1
0
D
7
1
0
IH
).
D
6
1
0
D
5
1
0
DATA BYTE
MCP414X/416X/424X/426X
D
4
1
0
D
3
1
0
D
2
1
0
7.5.2
The sequence to write to to a single non-volatile
memory location is the same as a single write to volatile
memory with the exception that after the CS pin is
driven inactive (V
started. A write cycle will not start if the write command
isn’t exactly 16 clocks pulses. This protects against
system issues from corrupting the Non-Volatile
memory locations.
After the CS pin is driven inactive (V
interface may immediately be re-enabled by driving the
CS pin to the active state (V
During an EEPROM write cycle, only serial commands
to Volatile memory (addresses 00h, 01h, 04h, and 05h)
are accepted. All other serial commands are ignored
until the EEPROM write cycle (t
allows the Host Controller to operate on the Volatile
Wiper registers and the TCON register, and to Read
the Status Register. The EEWA bit in the Status register
indicates the status of an EEPROM Write Cycle.
Once a write command to a Non-Volatile memory
location has been received, NO other SPI commands
should be received before the CS pin transitions to the
inactive state (V
have a Command Error (CMDERR) occur.
D
1
1
0
D
0
1 Valid Address/Command combination
0 Invalid Address/Command combination
SINGLE WRITE TO NON-VOLATILE
MEMORY
IH
IH
) or the current SPI command will
), the EEPROM write cycle (t
IL
or V
IHH
wc
) completes. This
DS22059B-page 49
).
IH
), the serial
(1)
WC
) is