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Device Specifications
Semiconductor Group
247
Note that PCON is not a bit-addressable register, so the above mentioned sequence for
entering the power-down mode is obtained by byte-handling instructions, as shown in the
following example:
ORL
PCON,#00000010
B
;Set bit PDE, bit PDS must not be set
ORL
PCON,#01000000
B
;Set bit PDS, bit PDE must not be set
The instruction that sets bit PDS is the last instruction executed before going into
power-down mode.
The only exit from power-down mode is a hardware reset. Reset will redefine all SFR’s, but will
not change the contents of the internal RAM.
In the power-down mode of operation,
V
CC
can be reduced to minimize power consumption. It
must be ensured, however, that
V
CC
is not reduced before the power- down mode is invoked,
and that
V
CC
is restored to its normal operating level, before the power-down mode is
terminated. The reset signal that terminates the power-down mode also restarts the oscillator.
The reset should not be activated before
V
CC
is restored to its normal operating level and must
be held active long enough to allow the oscillator to restart and stabilize (similar to power-on
reset).
Differences in Pin Assignments of the SAB 80C515 and SAB 80515
Since the SAB 80C515 is designed in CMOS technology, this device requires no
V
B B
pin, be-
cause the die’s substrate is internally connected to
V
CC
.
Furthermore, the RAM backup power supply via pin
V
PD
is replaced by the software- controlled
power-down mode and power supply via
V
CC
.
Therefore, pins
V
B B
and
V
PD
of the NMOS version SAB 80515 are used for other functions in
the SAB 80C515.
Pin 4 (the former pin
V
PD
) is the new PE pin which enables the use of the power saving modes.
Pin 37 (the former pin
V
BB
) becomes an additional
V
CC
pin. Thus, it is possible to insert a
decoupling capacitor between pin 37 (
V
CC
) and pin 38 (
V
SS
) very close to the device, thereby
avoiding long wiring and reducing the voltage distortion resulting from high dynamic current
peaks.
There is a difference between the NMOS and CMOS version concerning the clock circuitry.
When the device is driven from an external source, pin XTAL2 must be driven by the clock
signal; pin XTAL1, however, must be left open in the SAB 80C515 (must be tied low in the
NMOS version). When using the oscillator with a crystal there is no difference in the circuitry.
Thus, due to its pin compatibility the SAB 80C515 normally substitutes any SAB 80515 without
redesign of the user’s printed circuit board, but the user has to take care that the two
V
CC
pins
are hardwired on-chip. In any case, it is recommended that power is supplied on both
V
CC
pins
of the SAB 80C515 to improve the power supply to the chip.
If the power saving modes are to be used, pin PE must be tied low, otherwise these modes are
disabled.
*
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 ...