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Semiconductor Group
99
On-Chip Peripheral Components
7.6.1
Power Saving Modes of the SAB 80515/80535
The SAB 80515/80535 allows a reduction of the power consumption using the power-down mode.
7.6.1.1 Power-Down Mode of the SAB 80515/80535
The power-down mode in the SAB 80515/80535 allows a reduction of
V
CC
, to zero while saving 40
bytes of the on-chip RAM through a backup supply connected to the
V
PD
pin. In the following, the
terms
V
CC
and
V
PD
are used to specify the voltages on pin
V
CC
and pin
V
PD
, respectively.
lf
V
CC
>
V
PD
, the 40 bytes are supplied from
V
CC
.
V
PD
may then below. lf
V
CC
<
V
PD
, the current for
the 40 bytes is drawn from
V
PD
. The addresses of these backup-powered RAM locations range from
88 to 127 (58H to 7FH). The current drawn from the backup power supply is typically 1 mA, max. 3
mA.
To utilize this feature, the user’s system - upon detecting an imminent power failure - would interrupt
the processor in some manner to transfer relevant data to the 40-byte on-chip RAM and enable the
backup power supply to the
V
PD
pin. Then a reset should be accomplished before
V
CC
falls below
its operating limit. When power returns, a power-on reset should be accomplished, and the backup
supply needs to stay on long enough to resume normal operation. Figure 7-43 illustrates the timing
upon a power failure.
Figure 7-43
Reset and RAM Backup Power Timing of the SAB 80515/80535
*
Summary of Contents for SAB 80515 Series
Page 9: ...Semiconductor Group 9 Introduction Figure 1 2 Block Diagram ...
Page 12: ...Semiconductor Group 12 Fundamental Structure Figure 2 1 Detailed Block Diagram ...
Page 18: ...Semiconductor Group 18 Central Processing Unit Figure 3 1 Fetch Execute Sequence ...
Page 73: ...Semiconductor Group 73 On Chip Peripheral Components Figure 7 25 A D Converter Block Diagram ...
Page 83: ...Semiconductor Group 83 On Chip Peripheral Components Figure 7 33 a Timer 2 Block Diagram ...
Page 215: ...Device Specifications Semiconductor Group 215 ...
Page 217: ...Device Specifications Semiconductor Group 217 Pin Configuration P LCC 68 ...
Page 219: ...Device Specifications Semiconductor Group 219 Logic Symbol ...
Page 226: ...Device Specifications Semiconductor Group 226 Figure 1 Block Diagram ...
Page 229: ...Device Specifications Semiconductor Group 229 Figure 2 Memory Address Spaces ...
Page 239: ...Device Specifications Semiconductor Group 239 Figure 4 Block Diagram of the A D Converter ...
Page 241: ...Device Specifications Semiconductor Group 241 Figure 5 Interrupt Request Sources ...
Page 242: ...Device Specifications Semiconductor Group 242 Figure 6 Interrupt Priority Level Structure ...