MCP795W10-I/SL Microchip Technology, MCP795W10-I/SL Datasheet - Page 31

• Manufacturer Part Number: MCP795W10-I/SL
• Description: SPI GPP RTCC, 1Kb EE, 64B SRAM, WD Timer, Event Detect, ID 14 SOIC .150in TUBE
• Manufacturer: Microchip Technology

The debounce will only operate if the clock is running
and these timings are based on the uncalibrated
32.768 kHz clock.
• EVHS<1:0> – These bits determine how many
9.1.5
If the V
connected to GND. A low value series resistor and
Schottky diode are recommended between the
external battery and the V
current and also to prevent any leakage current
reaching the external V
The V
falls below 1.5V the system will continue to operate
the RTCC and SRAM using the V
~50mV hyst in the trip point changeover. The following
conditions apply:
FIGURE 9-2:
To write to the unique ID locations, the IDWRITE com-
mand is used. The device must be write enabled and
the correct unlock sequence must have been per-
formed. See
Register
 2011-2012 Microchip Technology Inc.
high-speed events must occur before the EVHIF
bit is set. All of these events must occur within
250 ms.
- 00 – 1st Event
- 01 – 4th Event
- 10 – 16th Event
- 11 – 32nd Event
SCK
Address range is 0x00-0x0F, address counter will wrap within this range.
CS
SO
TRIP
SI
BAT
for more details.
point is defined as 1.5V typical. When V
feature is not used, the V
V
BAT
0
0
Section 10.1.4, Write to the Unlock
0
SWITCHOVER
1
1
2
Instruction
IDREAD COMMAND SEQUENCE
BAT
1
3
source.
BAT
0
4
pin to reduce inrush
0
BAT
5
High-Impedance
BAT
1
6
supply. There is
pin should be
1
7
0
8
MCP795WXX/MCP795BXX
0
9 10 11 12 13 14 15 16 17 18 19 20 21 22
Preliminary
DD
0
Address Byte
0
3
TABLE 9-1:
For more information on V
Best Practices Application Note, AN1365 (DS01365).
9.1.6
When the unique ID locations are preprogrammed from
the factory with either an EUI-48 or EUI-64, the EUI
code is programmed into location 0x00-0x07. Loca-
tions 0x08-0x0F are blank (0x0F).
To read the unique ID location the IDREAD command
is given with the starting address. Valid addresses are
0x00 through 0x0F. All 16 bytes can be read out in a
single command by clocking the device. Trying to
access locations past 0x0F will result in the address
wrapping within these 16 bytes.
The ID locations can be written to using the IDWRITE
command. The valid address is between 0x00 and
0x0F. The entire 16 bytes must be written in two
groups of 8 bytes. A maximum of 8 bytes can be
written at once.
V
V
V
2
CC
CC
CC
Note:
< V
> V
> V
1 0
Condition
TRIP
TRIP
TRIP
Supply
UNIQUE ID LOCATIONS
For EUI-64, the data is located in address
0x00-0x07. For EUI-48 locations, 0x02-
0x07 contain the data. 0x00/01 contain
0xFF.
, V
, V
, V
7
CC
CC
CC
6
V
CONDITIONS
< V
< V
> V
BAT
5
BAT
BAT
BAT
Don’t Care
Data Out
CHANGOVER
BAT
4
Read/Write
conditions see the RTCC
3
Access
Yes
Yes
No
2
DS22280B-page 31
1
23
0
Powered
V
V
V
By
BAT
CC
CC