Flash Programming and Verification Waveforms - High-voltage Mode (V= 12V)PP PROGRAMMING VERIFICATION P1.0 - P1.7 ADDRESS ADDRESS P2.0 - P2.3 tAVQV PORT 0 DATA IN DATA OUT t t DVGL GHDX t t AVGL GHAX ALE/PROG t t SHGL t GHSL GLGH VPP LOGIC 1 EA/VPP LOGIC 0 tEHSH t tEHQZ ELQV P2.7 (ENABLE) tGHBL P3.4 (RDY/BSY) BUSY READY tWC Flash Programming and Verification Waveforms - Low-voltage Mode (V= 5V)PP PROGRAMMING VERIFICATION P1.0 - P1.7 ADDRESS ADDRESS P2.0 - P2.3 tAVQV PORT 0 DATA IN DATA OUT t t DVGL GHDX t t AVGL GHAX ALE/PROG tSHGL tGLGH LOGIC 1 EA/VPP LOGIC 0 tEHSH t tEHQZ ELQV P2.7 (ENABLE) tGHBL P3.4 (RDY/BSY) BUSY READY tWC 8AT89C51 Document Outline Block Diagram Features Description Pin Description VCC GND Port 0 Port 1 Port 2 Port 3 RST ALE/PROG PSEN EA/VPP XTAL1 XTAL2 Oscillator Characteristics Status of External Pins During Idle and Power-down Modes Lock Bit Protection Modes Programming the Flash Programming Interface Flash Programming Modes Flash Programming and Verification Waveforms - High-voltage Mode (VPP = 12V) Flash Programming and Verification Waveforms - Low-voltage Mode (VPP = 5V) Flash Programming and Verification Characteristics Absolute Maximum Ratings* DC Characteristics AC Characteristics External Program and Data Memory Characteristics External Program Memory Read Cycle External Data Memory Read Cycle External Data Memory Write Cycle External Clock Drive Waveforms External Clock Drive Serial Port Timing: Shift Register Mode Test Conditions Shift Register Mode Timing Waveforms AC Testing Input/Output Waveforms(1) Float Waveforms(1) Ordering Information