UPSD3422_06 Datasheet, PDF (248/293 Pages) STMicroelectronics – Turbo Plus Series Fast Turbo 8032 MCU with USB and Programmable Logic

PSD module
uPSD34xx
READ and WRITE operations. When CSI is driven to logic '1,' none of these memories are
available for selection, regardless of the address activity from the 8032, reducing power
consumption. The state of the PLD and port I/O pins are not changed when CSI goes to
logic ’1’ (disabled).
28.5.55
PLD non-turbo mode
The power consumption and speed of the PLDs are controlled by the Turbo Bit (Bit 3) in the
csiop PMMR0 register. By setting this bit to logic '1,' the Turbo mode is turned off and both
PLDs consume only stand-by current when ALL PLD inputs have no transitions for an
extended time (65ns for 5V devices, 100ns for 3.3 V devices), significantly reducing current
consumption. The PLDs will latch their outputs and go to standby, drawing very little current.
When Turbo mode is off, PLD propagation delay time is increased as shown in the AC
specifications for the PSD Module. Since this additional propagation delay also effects the
DPLD, the response time of the memories on the PSD Module is also lengthened by that
same amount of time. If Turbo mode is off, the user should add an additional wait state to the
8032 BUSCON SFR register if the 8032 clock frequency is higher that a particular value.
Please refer to Table 38 on page 82 in the MCU Module section.
The default state of the Turbo Bit is logic '0,' meaning Turbo mode is on by default (after
power-up and reset conditions) until it is turned off by the 8032 writing to PMMR0.
28.5.56
PLD current consumption
Figure 96 on page 259 and Figure 97 on page 260 (5V and 3.3V devices respectively) show
the relationship between PLD current consumption and the composite frequency of all the
transitions on PLD inputs, indicating that a higher input frequency results in higher current
consumption.
Current consumption of the PLDs have a DC component and an AC component. Both need
to be considered when calculating current consumption for a specific PLD design. When
Turbo mode is on, there is a linear relationship between current and frequency, and there is
a substantial DC current component consumed by the PSD Module when there are no
transitions on PLD inputs (composite frequency is zero). The magnitude of this DC current
component is directly proportional to how many product terms are used in the equations of
both PLDs. PSDsoft Express generates a “fitter” report that specifies how many product
terms were used in a design out of a total of 186 available product terms. Figure 96 on
page 259 and Figure 97 on page 260 both give two examples, one with 100% of the 186
product terms used, and another with 25% of the 186 product terms used.
28.5.57
Turbo mode current consumption
To determine the AC current component of the specific PLD design with Turbo mode on, the
user will have to interpolate from the graph, given the number of product terms specified in
the fitter report, and the estimated composite frequency of PLD input signal transitions. For
the DC component (y-axis crossing), the user can calculate the number by multiplying the
number of product terms used (from fitter report) times the DC current per product term
specified in the DC specifications for the PSD Module. The total PLD current usage is the
sum of its AC and DC components.
28.5.58
Non-turbo mode current consumption
Notice in Figure 96 on page 259 and Figure 97 on page 260 that when Turbo mode is off,
the DC current consumption is “zero” (just standby current) when the composite frequency
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