Datasheet AT89C51 (Microchip) - 9

AT89C51 Flash Programming and Verification Characteristics
T = 0°C to 70°C, V = 5.0 ± 10% A CC
Symbol Parameter Min Max Units
V (1) Programming Enable Voltage PP 11.5 12.5 V I (1) Programming Enable Current PP 1.0 mA 1/t Oscillator Frequency CLCL 3 24 MHz t Address Setup to PROG Low AVGL 48tCLCL t Address Hold after PROG GHAX 48tCLCL t Data Setup to PROG Low DVGL 48tCLCL t Data Hold after PROG GHDX 48tCLCL t P2.7 (ENABLE) High to V EHSH PP 48tCLCL t V Setup to PROG Low SHGL PP 10 µs t (1) V Hold after PROG GHSL PP 10 µs t PROG Width GLGH 1 110 µs t Address to Data Valid AVQV 48tCLCL t ENABLE Low to Data Valid ELQV 48tCLCL t Data Float after ENABLE 0 48t EHQZ CLCL tGHBL PROG High to BUSY Low 1.0 µs t Byte Write Cycle Time 2.0 ms WC Note: 1. Only used in 12-volt programming mode.
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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