4-6
BajaPPC-750: On-Card Memory Configuration
4.5 Real-Time Clock
The real-time clock for the BajaPPC-750 is provided by an M48T35 Timekeeper
SRAM device from SGS-Thomson Microelectronics. This is CMOS device with
32K x 8 of non-volatile RAM, integrated real-time clock, power-fail control cir-
cuitry, and lithium battery.
CAUTION.
There is a danger of explosion if the lithium battery is incor-
rectly replaced. Replace only with the same or equivalent type
recommended by the manufacturer. Dispose of used batteries
according to the manufacturer’s instructions.
The BajaPPC-750 utilizes a SNAPHAT
™
housing that allows the quartz crystal and
lithium cell to be mounted in a socket on top of the SRAM array and supporting
circuitry. The M48T35 is pin- and function-compatible with standard JEDEC
32K x 8 SRAMs. The real-time clock and NVRAM are mapped in the BajaPPC-750
memory space beginning at FF9C,0000
16
.
CAUTION.
Since the RTC registers deal with 100-year values, the software
must correctly set starting values to accommodate the year
2000 and beyond.
Address
(Hex)
Data
Function / Range
(BCD Format)
D7
D6
D5
D4
D3
D2
D1
D0
7FFF
10 Years
Year
Year / 00-99
7FFE
0
0
0
10 M.
Month
Month / 01-12
7FFD
0
0
10 Date
Date
Date / 01-31
7FFC
0
FT
0
0
0
Day
Day / 01-07
7FFB
0
0
10 Hours
Hours
Hour / 00-23
7FFA
0
10 Minutes
Minutes
Minutes / 00-59
7FF9
ST
10 Seconds
Seconds
Seconds / 00-59
7FF8
W
R
S
Calibration
Control
Register Map 4-3. BajaPPC-750 Real-Time Clock
Содержание BajaPPC-750
Страница 2: ...BajaPPC 750 PowerPC Based Single Board Computer User s Manual May 2002...
Страница 4: ...BajaPPC 750 PowerPC Based Single Board Computer User s Manual May 2002...
Страница 7: ......
Страница 16: ...0002M621 15 ix Register Map 9 1 Counter Timer Status CTSR 9 2 Register Map 9 2 Counter Timer Mode CTMR 9 4...
Страница 19: ...xii BajaPPC 750 Contents...
Страница 57: ...3 12 BajaPPC 750 Central Processing Unit May 2002...
Страница 77: ...5 12 BajaPPC 750 PMC PCI Interface May 2002...
Страница 111: ...6 34 BajaPPC 750 VMEbus Interface May 2002...
Страница 135: ...8 18 BajaPPC 750 Serial and Parallel I O May 2002...
Страница 207: ...10 68 BajaPPC 750 Monitor May 2002...