UPSD3212C Datasheet, PDF (120/152 Pages) STMicroelectronics – Flash Programmable System Devices with 8032 Microcontroller Core and 16Kbit SRAM

UPSD3212C, UPSD3212CV
Table 84. PSD MODULE Example, Typ. Power Calculation at V_CC = 5.0V (Turbo Mode Off)
Conditions
MCU Clock Frequency
= 12MHz
Highest Composite PLD input frequency
(Freq PLD)
= 8MHz
MCU ALE frequency (Freq ALE)
= 2MHz
% Flash memory
Access
= 80%
% SRAM access
= 15%
% I/O access
= 5% (no additional power above base)
Operational Modes
% Normal
= 40%
% Power-down Mode = 60%
Number of product terms used
(from fitter report)
= 45 PT
% of total product terms = 45/182 = 24.7%
Turbo Mode
= Off
Calculation (using typical values)
I_CC total
= I_CC(MCUactive) x %MCUactive + I_CC(PSDactive) x %PSDactive + I_PD(pwrdown) x %pwrdown
I_CC(MCUactive)
= 20mA
I_PD(pwrdown)
= 250µA
I_CC(PSDactive)
= I_CC(ac) + I_CC(dc)
= %flash x 2.5 mA/MHz x Freq ALE
+ %SRAM x 1.5 mA/MHz x Freq ALE
+ % PLD x (from graph using Freq PLD)
= 0.8 x 2.5 mA/MHz x 2MHz + 0.15 x 1.5 mA/MHz x 2MHz + 24 mA
= (4 + 0.45 + 24) mA
= 28.45mA
I_CC total
= 20mA x 40% + 28.45mA x 40% + 250µA x 60%
= 8mA + 11.38mA + 150µA
= 19.53mA
This is the operating power with no Flash memory Erase or Program cycles in progress. Calculation is based on all I/
O pins being disconnected and I_OUT = 0 mA.
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