Programming Model
http://www.motorola.com/computer/literature 3-45
3
Note These test modes are not intended to be used once the chip is in a
system.
Refresh/Scrub Address Register
ROW ADDRESS These bits form the row address counter used by the
refresher/scrubber for all blocks of DRAM. The row address counter
increments by one after each refresh/scrub cycle. When it reaches all 1s, it
rolls back over to all 0s and continues counting. ROW ADDRESS is
readable and writable for test purposes.
Note Within each block, the most significant bits of ROW ADDRESS
are used only when their DRAM devices are large enough to
require them.
Table 3-14. rtest encodings
rtest0,rtest1,rtest2 Test Mode selected
%000 Normal Counter Operation
%001 RA counts at 16x
%010 RA counts at 256x
%011 RA is always at roll value for CA
%100 CA counts at 16x
%101 CA counts at 256x
%110 reserved
%111 reserved
Address
$FEF80048
Bit
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
Name
0
0
0
ROW ADDRESS
0
0
0
COL ADDRESS
Operation
R
R
R
READ/WRITE
R
R
R
READ/WRITE
Reset
X
X
X
0 P
X
X
X
0 P