Hyundai GMS90X51C, GMS90X52C, GMS90X54C user manual Power Saving Modes

Page 27

GMS90X5XC Series

HYUNDAI MicroElectronics

Power Saving Modes

Two power down modes are available, the Idle Mode and Power Down Mode.

The bits PDE and IDLE of the register PCON select the Power Down mode or the Idle mode, respectively. If the Power Down mode and the Idle mode are set at the same time, the Power Down mode takes precedence. Table 10 gives a general overview of the power saving modes.

Table 10. Power Saving Modes Overview

	Entering
Mode	Instruction	Leaving by	Remarks
	Example

Idle mode	ORL PCON, #01H	- Enabled interrupt	CPU is gated off
		- Hardware Reset	CPU status registers maintain their
			data.
			Peripherals are active

Power-Down mode	ORL PCON, #02H	Hardware Reset	Oscillator is stopped, contents of on-
			chip RAM and SFR’s are maintained
			(leaving Power Down Mode means
			redefinition of SFR contents).

In the Power Down mode of operation, VCC can be reduced to minimize power consumption. It must be ensured, however, that VCC is not reduced before the Power Down mode is invoked, and that VCC 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 VCC 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).

Jan. 2001 Ver 1.0

23

Image 27

Contents GMS90X51C GMS90X52C GMS90X54C Page Mask GMS90C51C Block DiagramGMS90C52C/54C GMS90L52C/54CLow voltage versions Plcc Pin Configuration top view PIN ConfigurationEA / VPP ALE / Prog Pdip Pin Configuration top viewMqfp Pin Configuration top view Logic Symbol XTAL2 PIN Definitions and FunctionsPin Number Symbol FunctionProgram Store Enable ResetAddress Latch Enable Circuit ground potentialNo connection Functional Description Block Diagram of the GMS90X5XC seriesSpecial Function Register PSW CPUSpecial Function Registers E0H C0HD0H FFH D8HD0H Contents of SFRs, SFRs in Numeric Order Address RegisterE0H F0HGF1 GF0 PDE Idle C8H T2CON TF2 EXF2 Rclk Tclk EXEN2 TR2 CP/RL2 Clock Generation Diagram X2 ModeMode Swithcing Waveforms Input Clock Timer / Counter 0Timer/Counter 0 and 1 Operating Modes Description TmodT2EX TimerTimer/Counter 2 Operating Modes P1.1 Remarks Input ClockSM0 SM1 Serial Interface UsartUsart Operating Modes Baudrate DescriptionInterrupt Request Sources Interrupt SystemInterrupt Priority-Within-Level Interrupt Source Power Saving Modes Absolute Maximum Ratings Electrical CharacteristicsDC Characteristics for GMS90C51C/52C/54C Parameter Symbol Limit Values Unit Test Conditions MinPower supply current Hyundai MicroElectronics VCC= 3.3V + 0.3V, -0.6V VSS=0V TA= 0C to 70C DC Characteristics for GMS90L51C/52C/54CExplanation of the AC Symbols AC Characteristics for GMS90X5XC series 12MHz versionExternal Program Memory Characteristics GMS90X5XC Series Advance Information 12MHz External Clock Drive AC Characteristics for GMS90X5XC series 16MHz version Advance Information 16MHz External Clock Drive AC Characteristics for GMS90X5XC series 24MHz version Advance Information 24MHz External Clock Drive AC Characteristics for GMS90X5XC series 33MHz version Advance Information 33MHz External Clock Drive AC Characteristics for GMS90X5XC series 40MHz version Advance Information 40MHz External Clock Drive External Program Memory Read Cycle External Data Memory Read Cycle AC Testing Input, Output Waveforms Oscillator Circuit 44PLCC Plastic Package P-LCC-44Plastic Package P-DIP-40 Plastic Package P-MPQF-44 GMS90X5XC Series ROM Protection GMS90X5XC-GC