MCP414X/416X/424X/426X
7.4
Continuous Commands
Note 1: It is recommended that while the CS pin is
active, only one type of command should
be issued. When changing commands, it
is recommended to take the CS pin
inactive then force it back to the active
state.
The device supports the ability to execute commands
continuously. While the CS pin is in the active state (VIL
or VIHH). Any sequence of valid commands may be
received.
The following example is a valid sequence of events:
2: It is also recommended that long
command strings should be broken down
into shorter command strings. This
reduces the probability of noise on the
SCK pin corrupting the desired SPI
command string.
1. CS pin driven active (VIL or VIHH).
2. Read Command.
3. Increment Command (Wiper 0).
4. Increment Command (Wiper 0).
5. Decrement Command (Wiper 1).
6. Write Command (Volatile memory).
7. Write Command (Non-Volatile memory).
8. CS pin driven inactive (VIH).
TABLE 7-3:
COMMANDS
Operates on
Volatile/
Non-Volatile (VIHH) on
High
Voltage
Works
when
Wiper is
“locked”?
Writes
Value in
EEPROM
Impact on
WiperLock or
Write Protect
# of
Bits
Command Name
memory
CS pin?
Write Data
16-Bits
16-Bits
8-Bits
8-Bits
16-Bits
16-Bits
8-Bits
8-Bits
8-Bits
Yes (1)
—
Both
Both
—
—
unlocked (1)
unlocked (1)
unlocked (1)
unlocked (1)
unchanged
unchanged
unchanged
unchanged
No
No
No
No
No
Yes
No
No
Yes
Read Data
Increment Wiper
—
Volatile Only
Volatile Only
Both
—
Decrement Wiper
—
—
High Voltage Write Data
High Voltage Read Data
High Voltage Increment Wiper
High Voltage Decrement Wiper
Yes
—
Yes
Yes
Yes
Yes
Yes
Both
—
Volatile Only
Volatile Only
—
(2)
Modify Write Protect or Wiper-
Lock Technology (High Voltage) -
Enable
—
Non-Volatile
Only (2)
locked/
protected (2)
(3)
Modify Write Protect or Wiper-
Lock Technology (High Voltage) -
Disable
8-Bits
—
Non-Volatile
Only (3)
Yes
unlocked/
unprotected
Yes
(3)
Note 1: This command will only complete if wiper is “unlocked” (WiperLock Technology is Disabled).
2: If the command is executed using address 02h or 03h, then that corresponding wiper is locked or
if with address 0Fh, then Write Protect is enabled.
3: If the command is executed using with address 02h or 03h, then that corresponding wiper is unlocked or
if with address 0Fh, then Write Protect is disabled.
DS22059B-page 48
© 2008 Microchip Technology Inc.
MICROCHIP [ MICROCHIP ]
