Address/command byte, Address/command byte figure 4, Rtc/watchdog address map figure 5 – Rainbow Electronics DS1680 User Manual
Page 6
DS1680
6 of 23
ADDRESS/COMMAND BYTE
Figure 4 shows the command byte for the DS1680. Each data transfer is initiated by a command byte.
Bits 0–6 specify the address of the registers to be accessed. The MSB (bit 7) is the read/write bit. This bit
specifies whether the accessed byte will be read or written. A read operation is selected if bit 7 is a zero
and a write operation is selected if bit 7 is a one. The address map for the DS1680 is shown in Figure 5.
ADDRESS/COMMAND BYTE Figure 4
7
6
5
4
3
2
1
0
RD
WR
A6
A5
A4
A3
A2
A1
A0
RTC/WATCHDOG ADDRESS MAP Figure 5
BIT7
BIT0
00
0
10 SECONDS
SECONDS
01
0
10 MINUTES
MINUTES
10 HR
02
0
12
24
A/P
10 HR
HOURS
03
0
0
0
0
0
DAY
04
0
0
10 DATE
DATE
05
0
0
0
10 MO.
MONTH
06
10 YEAR
YEAR
07
M
10 SEC ALARM
SECONDS ALARM
08
M
10 MIN ALARM
MINUTES ALARM
10 HR
09
M
12
24
A/P
10 HR
HOUR ALARM
0A
M
0
0
0
0
DAY ALARM
0B
CONTROL REGISTER
0C
STATUS REGISTER
0D
WATCHDOG REGISTER
0E
7F
RESERVED