FM33256/FM3316 SPI Companion w/ FRAM
Register Description
Address
Description
1Dh
Alarm – Month
D7
D6
D5
D4
D3
D2
D1
D0
M
0
0
10 Month
Month.3
Month.2
Month.1
Month.0
Contains the alarm value for the month and the mask bit to select or deselect the Month value.
Match. Setting this bit to 0 causes the Month value to be used in the alarm match logic. Setting this bit to 1
causes the match circuit to ignore the Month value. Battery-backed, read/write.
/M
1Ch
Alarm – Date
D7
D6
D5
D4
D3
D2
D1
D0
M
0
10 date.1
10 date.0
Date.3
Date.2
Date.1
Date.0
Contains the alarm value for the date and the mask bit to select or deselect the Date value.
/M
Match: Setting this bit to 0 causes the Date value to be used in the alarm match logic. Setting this bit to 1 causes
the match circuit to ignore the Date value. Battery-backed, read/write.
1Bh
Alarm – Hours
D7
D6
D5
D4
D3
D2
D1
D0
M
0
10 hours.1
10 hours.0
Hours.3
Hours2
Hours.1
Hours.0
Contains the alarm value for the hours and the mask bit to select or deselect the Hours value.
/M
Match: Setting this bit to 0 causes the Hours value to be used in the alarm match logic. Setting this bit to 1 causes
the match circuit to ignore the Hours value. Battery-backed, read/write.
1Ah
Alarm – Minutes
D7
D6
D5
D4
D3
D2
D1
D0
M
10 min.2
10 min.1
10 min.0
Min.3
Min.2
Min.1
Min.0
Contains the alarm value for the minutes and the mask bit to select or deselect the Minutes value
/M
Match: Setting this bit to 0 causes the Minutes value to be used in the alarm match logic. Setting this bit to 1
causes the match circuit to ignore the Minutes value. Battery-backed, read/write.
19h
Alarm – Seconds
D7
D6
D5
D4
D3
D2
D1
D0
M
10 sec.2
10 sec.1
10 sec.0
Seconds.3
Seconds.2
Seconds.1
Seconds.0
Contains the alarm value for the seconds and the mask bit to select or deselect the Seconds value.
/M
Match: Setting this bit to 0 causes the Seconds value to be used in the alarm match logic. Setting this bit to 1
causes the match circuit to ignore the Seconds value. Battery-backed, read/write.
18h
Companion Control
D7
D6
D5
D4
D3
D2
D1
D0
SNL
AL/SW
F1
F0
VBC
FC
VTP1
VTP0
SNL
Serial Number Lock: Setting to a ‘1’ makes registers 10h to 17h and SNL read-only. SNL cannot be cleared once
set to ‘1’. Nonvolatile, read/write.
AL/SW
Alarm/Square Wave Select: When set to ‘1’, the alarm match drives the ACS pin as well as the AF flag. When
set to ‘0’, the selected Square Wave Freq will be driven on the ACS pin, and an alarm match only sets the AF
flag. Nonvolatile, read/write.
F(1:0)
Square Wave Freq Select: These bits select the frequency on the ACS pin when the CAL and AL/SW bits are
both ‘0’. Nonvolatile.
Setting
1 Hz
12 Hz
F(1:0)
00 (default)
01
Setting
4096 Hz
32768Hz
F(1:0)
10
11
5
VBC
VBAK Charger Control: Setting VBC to ‘1’ (and FC=0) causes a 80 µA (1 mA if FC=1) trickle charge current to
be supplied on VBAK. Clearing VBC to ‘0’ disables the charge current. Battery-backed, read/write.
FC
Fast Charge: Setting FC to ‘1’ (and VBC=1) causes a ~1 mA trickle charge current to be supplied on VBAK.
Clearing VBC to ‘0’ disables the charge current. Battery-backed, read/write.
VTP Select. These bits control the reset trip point for the low-VDD reset function. When VDD is below the
selected VTP voltage, the reset pin /RST will drive low and the SPI interface will be locked out. Nonvolatile,
read/write.
VTP(1:0)
Rev. 1.0
Dec. 2006
Page 13 of 28
RAMTRON [ RAMTRON INTERNATIONAL CORPORATION ]
