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(6) Refresh control
The TMP92CZ26A supports two kinds of refresh commands: Auto Refresh and Self Refresh.
(a) Auto Refresh
When SDRCR<SRC> is set to "1", the Auto Refresh command is automatically issued at
intervals specified by SDRCR<SRS2:0>. The Auto Refresh interval can be specified in a
range of 47 states to 1248 states (0.78 μs to 20.8 μs at f
The CPU operation (instruction fetch and execution) is halted while the Auto Refresh
command is being executed. Figure3.10.6 shows the Auto Refresh cycle timing, and
Table3.10.3 shows the Auto Refresh interval settings. The Auto Refresh function cannot be
used in IDLE1 and STOP modes. In these modes, use the Self Refresh function to be
explained next.
Note: A system reset disables the Auto Refresh function.
SDRCR<SRS2:0>
SRS2
SRS1
SRS0
0
0
0
0
0
1
0
1
0
0
1
1
1
0
0
1
0
1
1
1
0
1
1
1
SDCLK
SDCKE
SDLUDQM
SDLLDQM
SDCS
SDRAS
SDCAS
SDWE
Figure3.10.6 Auto Refresh Cycle Timing
Table3.10.3 Auto Refresh Intervals
Auto
Refresh
Interval
6 MHz
(states)
47
7.8
78
13.0
156
26.0
312
52.0
468
78.0
624
104.0
936
156.0
1248
208.0
92CZ26A-231
= 60 MHz).
SYS
2 states
Auto Refresh
Frequency (System Clock)
10 MHz
20 MHz
40 MHz
4.7
2.4
1.18
7.8
3.9
1.95
15.6
7.8
3.90
31.2
15.6
7.80
46.8
23.4
11.70
62.4
31.2
15.60
93.6
46.8
23.40
124.8
62.4
31.20
TMP92CZ26A
Unit [ μ s]
60 MHz
80 MHz
0.78
0.59
1.30
0.98
2.60
1.95
5.20
3.90
7.80
5.85
10.40
7.80
15.60
11.70
20.80
15.60
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