Datasheet
Table Of Contents
- Features
- Description
- Block Diagram
- SFR Mapping
- Pin Configurations
- Oscillators
- Enhanced Features
- Dual Data Pointer Register DPTR
- Expanded RAM (XRAM)
- Reset
- Power Monitor
- Timer 2
- Programmable Counter Array PCA
- Serial I/O Port
- Interrupt System
- Power Management
- Keyboard Interface
- 2-wire Interface (TWI)
- Serial Port Interface (SPI)
- Hardware Watchdog Timer
- ONCE(TM) Mode (ON Chip Emulation)
- Power-off Flag
- EEPROM Data Memory
- Reduced EMI Mode
- Flash Memory
- Electrical Characteristics
- Absolute Maximum Ratings
- DC Parameters
- AC Parameters
- Explanation of the AC Symbols
- External Program Memory Characteristics
- External Program Memory Read Cycle
- External Data Memory Characteristics
- External Data Memory Write Cycle
- External Data Memory Read Cycle
- Serial Port Timing - Shift Register Mode
- Shift Register Timing Waveforms
- External Clock Drive Waveforms
- AC Testing Input/Output Waveforms
- Float Waveforms
- Clock Waveforms
- Ordering Information
- Packaging Information
- Table of Contents
113
AT89C51ID2
4289C–8051–11/05
Read Data The following procedure is used to read the data stored in the EEPROM memory:
• Check EEBUSY flag
• If the user application interrupts routines use XRAM memory space: Save and
disable interrupts.
• Load DPTR with the address to read
• Set bit EEE of EECON register
• Execute a MOVX A, @DPTR
• Clear bit EEE of EECON register
• Restore interrupts.
Figure 44. Recommended EEPROM Data Read Sequence
EEPROM Data Read
Sequence
Data Read
DPTR= Address
ACC= Data
Exec: MOVX A, @DPTR
Last Byte
to Read?
EEPROM Data Mapping
EECON = 02h (EEE=1)
EEPROM Data Mapping
EECON = 00h (EEE = 0
Save & Disable IT
EA= 0
Restore IT
EEBusy
Cleared?