Real Time Clock DS12887 by Dallas Semiconductor
Program functions
Read
All registers and the User RAM are
read into the buffer.
Program
All writetable registers and
the User RAM are programmed with data from the
buffer.
Compare
All writeable registers and the
User RAM are compared with data in the buffer.
Erase
The Timekeeping and Control
Registers are programmed as follows:
|
Register: |
0 |
1 |
2 |
3 |
4 |
5 |
6 |
7 |
8 |
9 |
A |
B |
|
Value: |
0h |
0h |
0h |
0h |
1h |
1h |
1h |
1h |
1h |
0h |
0h |
80h |
The User RAM is filled with FFh value.
Blank Check
All writeable registers and
the User RAM are checked for the empty value (see
'Erase').
|
Note 1: |
For Program/Erase the device will first be 'frozen' by setting the bit 7 of Control Register B (SET) to '1' and after programming and verifying it will be set to value defined by the user for 'Program' or kept on '1' for 'Erase'. |
|
Note 2: |
At 'Program', 'Compare', 'Erase' and 'Blank Check' the read-only registers Ch, Dh are ignored and not programmed/verified. |
|
Note 3: |
There is no checking against incorrect values during programming, so the user must take care of this. |