fm3316 Ramtron Corporation, fm3316 Datasheet - Page 12

• Manufacturer Part Number: fm3316
• Description: 3v Integrated Processor Companion With Memory
• Manufacturer: Ramtron Corporation

Register Map
The RTC and processor companion functions are accessed via 30 special function registers, which are mapped to
unique op-codes. The interface protocol is described on page 17. The registers contain timekeeping data, alarm
settings, control bits, and information flags. A description of each register follows the summary table.
Register Map Summary Table
Battery-backed =
Note: When the device is first powered up and programmed, all timekeeping registers must be written because the battery-
backed register values cannot be guaranteed. The table below shows the default values of the non-volatile registers and some of
the battery-backed bits. All other register values should be treated as unknown
Default Register Values
Rev. 1.1
Dec. 2007
Address
Address
1Dh
1Ch
0Dh
0Ch
1Bh
1Ah
19h
18h
17h
16h
15h
14h
13h
12h
11h
10h
0Fh
0Eh
0Bh
0Ah
09h
08h
07h
06h
05h
04h
03h
02h
01h
00h
1Dh
1Ch
1Bh
1Ah
19h
18h
17h
16h
15h
14h
13h
/OSCEN
/Match
/Match
/Match
/Match
/Match
EWDF
WDE
Hex Value
NVC
SNL
D7
0
0
0
0
0
0
-
-
-
0x81
0x81
0x80
0x80
0x80
0x40
0x00
0x00
0x00
0x00
0x00
AL/SW
LWDF
D6
AF
0
0
0
0
0
0
0
-
-
-
-
-
10 years
Nonvolatile =
Alarm 10 seconds
Alarm 10 minutes
10 seconds
10 minutes
CALS
POR
Alarm 10 hours
D5
CF
F1
0
0
0
-
-
-
-
10 hours
10 date
10 date
Event Counter Byte 1
Event Counter Byte 0
WDSET4
Serial Number Byte 7
Serial Number Byte 6
Serial Number Byte 5
Serial Number Byte 4
Serial Number Byte 3
Serial Number Byte 2
Serial Number Byte 1
Serial Number Byte 0
WDST4
Address
10 mo
10 mo
CAL4
AEN
D4
F0
LB
0
-
-
12h
11h
10h
0Fh
0Eh
0Dh
0Ch
0Bh
01h
00h
BB/NV User Programmable =
reserved
WDET3
WDST3
CAL3
WR3
VBC
RC
D3
0
-
Hex Value
0x00
0x00
0x00
0x00
0x00
0x01
0x00
0x00
0x00
0x80
WDET2
WDST2
CAL2
WR2
CAL
WC
Alarm seconds
D2
FC
Alarm minutes
Alarm months
-
Alarm hours
Alarm date
seconds
minutes
months
hours
years
date
FM33256/FM3316 SPI Companion w/ FRAM
WDST1
WDET1
.
VTP1
POLL
CAL1
WR1
day
D1
W
-
WDET0
WDST0
VTP0
CAL0
WR0
D0
CP
R
-
Function
Alarm Month
Alarm Date
Alarm Hours
Alarm Minutes
Alarm Seconds
Companion Control
Serial Number 7
Serial Number 6
Serial Number 5
Serial Number 4
Serial Number 3
Serial Number 2
Serial Number 1
Serial Number 0
Event Counter 1
Event Counter 0
Event Counter Control
Watchdog Control
Watchdog Control
Watchdog Restart
Watchdog Flags
Years
Month
Date
Day
Hours
Minutes
Seconds
CAL/Control
RTC/Alarm Control
Page 12 of 28
Range
01-12
01-31
00-23
00-59
00-59
FFh
FFh
FFh
FFh
FFh
FFh
FFh
FFh
FFh
FFh
00-99
01-12
01-31
01-07
00-23
00-59
00-59