6.8 Practical Examples of Implementation …
627
Figure 6.97d shows the electrical circuit and designation of another element implementing the logical conjunction function (&
E ) from supply voltage values of several
injectors. The circuit operates in the following manner. When the E
1
p is powered,
TI is open and T2 is closed. The voltage at the common point “c” of the collectors
depends on the state of T4, which is opened only if the voltage E
1
p is present at its
injector, and the transistor T3 is opened. High potential appears at the output of the
circuit in the point “c” only in case of simultaneous presence of E
1
p and E
2
p , i.e.
C = E
1
|E
2 .
Let us consider features of PCS operation within an LSIC MP. Time delay of one
of the LSIC MP supply voltages (e.g., E
2 E
2
n ) can be implemented by connecting the
condenser C (Fig. 6.97e) to the corresponding power output of the LSIC I
2 L. After
power-on, the delay in the appearance of voltage E
2 relative to E
1
p can be roughly
estimated using the formula, where R is the resistance of the current-carrying LSIC
register; C is the capacitance rating; U is the capacitance potential; E is the potential
at the current-carrying resistor.
In case of such activation of the condenser C, after activation of power supply of
the onboard chain, a S2 signal will be generated inside the LSIc, which will set the
register of microcommands in the 0000000000 state. This state is decoded in the SD
block during the following clock cycle and preserved at the LSIC output during eight
clock cycles (M = 3). During this time, power will be enabled on all ICs and LSICs of
the microcomputer, which will be registered by the circuit &
E . The microcomputer
will start operating according to the microprogram starting with the 00000 00000 of
the microprogram memory and setting it to the initial set state.
In case of a short-term power-off for the time t < t, the PCS will form the signal
S1 that will switch the stack register of the microcommands address (MCA) to
another level and set it in the 1110000000 state. The microcomputer will enter the
microprogram of power outage handling. By switching the capacitance C to another
LSIC power output (E
1
p ), it is possible to reprogram addresses of power-on and
power-off microprograms. Therefore, the examined PCS structure makes it possible
not only to register and identify moments of initial activation and power failures
of the microcomputer, but also allows for reprogramming of the addresses of the
corresponding microprograms by the LSIC user.
Implementation of the PCS embedded in LSIC I
2 L ensures the following
advantages as compared to their implementation outside LSICs:
– It is possible to directly influence internal LSIC nodes without introduction of
additional time delays by buffer circuits;
– The need to introduce addition pins in the LSIC designed for its initial installation
is excluded;
– The quantity of equipment pieces necessary to build the microcomputer is reduced,
and its reliability is increased.
As follows from the above, without knowing the above algorithm of the PCS operation and physical operation mechanisms of its elements (disjunctor and conjunctor),
627
Figure 6.97d shows the electrical circuit and designation of another element implementing the logical conjunction function (&
E ) from supply voltage values of several
injectors. The circuit operates in the following manner. When the E
1
p is powered,
TI is open and T2 is closed. The voltage at the common point “c” of the collectors
depends on the state of T4, which is opened only if the voltage E
1
p is present at its
injector, and the transistor T3 is opened. High potential appears at the output of the
circuit in the point “c” only in case of simultaneous presence of E
1
p and E
2
p , i.e.
C = E
1
|E
2 .
Let us consider features of PCS operation within an LSIC MP. Time delay of one
of the LSIC MP supply voltages (e.g., E
2 E
2
n ) can be implemented by connecting the
condenser C (Fig. 6.97e) to the corresponding power output of the LSIC I
2 L. After
power-on, the delay in the appearance of voltage E
2 relative to E
1
p can be roughly
estimated using the formula, where R is the resistance of the current-carrying LSIC
register; C is the capacitance rating; U is the capacitance potential; E is the potential
at the current-carrying resistor.
In case of such activation of the condenser C, after activation of power supply of
the onboard chain, a S2 signal will be generated inside the LSIc, which will set the
register of microcommands in the 0000000000 state. This state is decoded in the SD
block during the following clock cycle and preserved at the LSIC output during eight
clock cycles (M = 3). During this time, power will be enabled on all ICs and LSICs of
the microcomputer, which will be registered by the circuit &
E . The microcomputer
will start operating according to the microprogram starting with the 00000 00000 of
the microprogram memory and setting it to the initial set state.
In case of a short-term power-off for the time t < t, the PCS will form the signal
S1 that will switch the stack register of the microcommands address (MCA) to
another level and set it in the 1110000000 state. The microcomputer will enter the
microprogram of power outage handling. By switching the capacitance C to another
LSIC power output (E
1
p ), it is possible to reprogram addresses of power-on and
power-off microprograms. Therefore, the examined PCS structure makes it possible
not only to register and identify moments of initial activation and power failures
of the microcomputer, but also allows for reprogramming of the addresses of the
corresponding microprograms by the LSIC user.
Implementation of the PCS embedded in LSIC I
2 L ensures the following
advantages as compared to their implementation outside LSICs:
– It is possible to directly influence internal LSIC nodes without introduction of
additional time delays by buffer circuits;
– The need to introduce addition pins in the LSIC designed for its initial installation
is excluded;
– The quantity of equipment pieces necessary to build the microcomputer is reduced,
and its reliability is increased.
As follows from the above, without knowing the above algorithm of the PCS operation and physical operation mechanisms of its elements (disjunctor and conjunctor),