FM33256B-G Cypress Semiconductor, FM33256B-G Datasheet - Page 13

• Manufacturer Part Number: FM33256B-G
• Description: Real Time Clock 256Kb F-RAM Processor Companion
• Manufacturer: Cypress Semiconductor

Specifications of FM33256B-G

• Rohs: yes
• Supply Voltage - Max: 3.6 V
• Supply Voltage - Min: 2.7 V
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Mounting Style: SMD/SMT
• Package / Case: SOIC-14
• Factory Pack Quantity: 56

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 18. 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
This product conforms to specifications per the terms of the Ramtron
standard warranty. The product has completed Ramtron’s internal
qualification testing and has reached production status.
Rev. 3.0
Aug. 2012
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
/OSCEN
/Match
/Match
/Match
/Match
/Match
EWDF
WDE
NVC
SNL
D7
0
0
0
0
0
0
-
-
-
AL/SW
LWDF
D6
AF
0
0
0
0
0
0
0
-
-
-
-
-
Address
10 years
Nonvolatile =
Alarm 10 seconds
Alarm 10 minutes
10 seconds
10 minutes
1Dh
1Ch
1Bh
1Ah
19h
18h
17h
16h
15h
14h
13h
CALS
POR
Alarm 10 hours
D5
CF
F1
0
0
0
-
-
-
-
10 hours
10 date
10 date
Hex Value
0x81
0x81
0x80
0x80
0x80
0x40
0x00
0x00
0x00
0x00
0x00
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
10 mo
10 mo
CAL4
AEN
D4
LB
F0
0
-
-
Default Register Values
BB/NV User Programmable =
reserved
WDET3
WDST3
CAL3
WR3
VBC
RC
D3
0
-
WDET2
WDST2
CAL2
WR2
CAL
WC
Alarm seconds
D2
FC
Alarm minutes
Alarm months
-
Alarm hours
Alarm date
seconds
minutes
Address
months
hours
years
date
WDET1
WDST1
.
VTP1
POLL
CAL1
WR1
12h
11h
10h
0Fh
0Eh
0Dh
0Ch
0Bh
01h
00h
day
D1
W
-
1850 Ramtron Drive, Colorado Springs, CO 80921
FM33256B SPI Companion w/ FRAM
Hex Value
WDET0
WDST0
VTP0
CAL0
WR0
0x00
0x00
0x00
0x00
0x00
0x01
0x00
0x00
0x00
0x80
Ramtron International Corporation
CP
D0
R
-
(800) 545-FRAM, [phone]
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
www.ramtron.com
Page 13 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