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16Mb: 1 Meg x 16 Async/Page/Burst CellularRAM 1.0 Memory
Configuration Registers
Table 6:
16Mb Address Patterns for PAR (RCR[4] = 1)
RCR[2]
0
0
0
0
1
1
1
1
RCR[1]
0
0
1
1
0
0
1
1
RCR[0]
0
1
0
1
0
1
0
1
Active Section
Full die
One-half of die
One-quarter of die
One-eighth of die
None of die
One-half of die
One-quarter of die
One-eighth of die
Address Space
000000h–0FFFFFh
000000h–07FFFFh
000000h–03FFFFh
000000h–01FFFFh
0
80000h–0FFFFFh
C0000h–0FFFFFh
E0000h–0FFFFFh
Size
1 Meg x 16
512K x 16
256K x 16
128K x 16
0 Meg x 16
512K x 16
256K x 16
128K x 16
Density
16Mb
8Mb
4Mb
2Mb
0Mb
8Mb
4Mb
2Mb
Deep Power-Down (RCR[4]) Default = DPD Disabled
The deep power-down bit enables and disables all refresh-related activity. This mode is
used if the system does not require the storage provided by the CellularRAM device. Any
stored data will become corrupted when DPD is enabled. When refresh activity has been
re-enabled, the CellularRAM device will require 150μs to perform an initialization proce-
dure before normal operations can resume.
Deep power-down is enabled when RCR[4] = 0, and remains enabled until RCR[4] is set to
“1.” DPD should not be enabled or disabled with the software access sequence; instead,
use CRE to access the RCR.
Temperature-Compensated Refresh (RCR[6:5]) Default = On-Chip Temperature Sensor
This CellularRAM device includes an on-chip temperature sensor that automatically
adjusts the refresh rate according to the operating temperature. The on-chip TCR is
enabled by clearing both of the TCR bits in the refresh configuration register (RCR[6:5] =
00b). Any other TCR setting enables a fixed refresh rate. When the on-chip temperature
sensor is enabled, the device continually adjusts the refresh rate according to the oper-
ating temperature.
The TCR bits also allow for adequate fixed-rate refresh at three different temperature
thresholds (+15°C, +45°C, and +85°C). The setting selected must be for a temperature
higher than the case temperature of the CellularRAM device. If the case temperature
is +35°C, the system can minimize self refresh current consumption by selecting the
+45°C setting. The +15°C setting would result in inadequate refreshing and cause
data corruption.
Page Mode Operation (RCR[7]) Default = Disabled
The page mode operation bit determines whether page mode is enabled for asynchro-
nous READ operations. In the power-up default state, page mode is disabled.
PDF: 09005aef81cb58ed/Source: 09005aef81c7a667
16mb_burst_cr1_0_p23z_2.fm - Rev. H 4/08 EN
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