10 real-time clock and non-volatile ram, Real-time clock and non-volatile ram -10 – Acrosser AR-B1320 User Manual
Page 18
A
A
R
R
-
-
B
B
1
1
3
3
2
2
0
0
U
U
s
s
e
e
r
r
’
’
s
s
G
G
u
u
i
i
d
d
e
e
2.10 REAL-TIME
CLOCK
AND NON-VOLATILE RAM
The AR-B1320 contains a real-time clock compartment that maintains the date and time in
addition to storing configuration information about the computer system. It contains 14 bytes of
clock and registers and 114 bytes of general purpose RAM. Because of the use of CMOS
technology, it consumes very little power and can be maintained for long periods of time using an
internal lithium battery.
Address Description
00 Seconds
01 Second
alarm
02 Minutes
03 Minute
alarm
04 Hours
05 Hour
alarm
06
Day of week
07
Date of month
08 Month
09 Year
0A
Status register A
0B
Status register B
0C
Status register C
0D
Status register D
0E
Diagnostic status byte
0F
Shutdown status byte
10
Diskette drive type byte, drive A and B
11
Fixed disk type byte, drive C
12
Fixed disk type byte, drive D
13 Reserved
14 Equipment
byte
15
Low base memory byte
16
High base memory byte
17
Low expansion memory byte
18
High expansion memory byte
19-2D Reserved
2E-2F
2-byte CMOS checksum
30
Low actual expansion memory byte
31
High actual expansion memory byte
32
Date century byte
33
Information flags (set during power on)
34-7F
Reserved for system BIOS
Table 2-5 Real-Time Clock & Non-Volatile RAM
2-10