AT89LP51 Atmel Corporation, AT89LP51 Datasheet - Page 11

• Manufacturer Part Number: AT89LP51
• Manufacturer: Atmel Corporation

Specifications of AT89LP51

• Flash (kbytes): 4 Kbytes
• Max. Operating Frequency: 20 MHz
• Cpu: 8051-1C
• Max I/o Pins: 36
• Uart: 1
• Sram (kbytes): 0.25
• Eeprom (bytes): 256
• Self Program Memory: IAP
• Operating Voltage (vcc): 2.4 to 5.5
• Timers: 3
• Isp: SPI
• Watchdog: Yes

3. Memory Organization
3.1
3709D–MICRO–12/11
Program Memory
Table 2-3.
The AT89LP51/52 uses a Harvard Architecture with separate address spaces for program and
data memory. The program memory has a regular linear address space with support for 64K
bytes of directly addressable application code. The data memory has 256 bytes of internal RAM
and 128 bytes of Special Function Register I/O space. The AT89LP51/52 supports up to 64K
bytes of external data memory, with portions of the external data memory space implemented on
chip as nonvolatile Flash data memory. External program memory is supported for addresses
above 8K. The memory address spaces of the AT89LP51/52 are listed in
Table 3-1.
The AT89LP51/52 contains 4K/8K bytes of on-chip In-System Programmable Flash memory for
program storage, plus support for up to 60K/56K bytes of external program memory. The Flash
memory has an endurance of at least 10,000 write/erase cycles and a minimum data retention
time of 10 years. The reset and interrupt vectors are located within the first 83 bytes of program
memory (refer to
program memory address space for access by the MOVC instruction. A map of the
AT89LP51/52 program memory is shown in
Feature
Pin Sampling Rate (INT0, INT1, T0, T1, T2, T2EX)
Minimum RST input pulse in System Clocks
WDIDLE and DISRTO bit locations
Name
DATA
IDATA
SFR
FDATA
XDATA
CODE
XCODE
SIG
AT89LP51/52 Memory Address Spaces
Compatibility Mode versus Fast Mode Summary
Table 9-1 on page
Description
Directly addressable internal RAM
Indirectly addressable internal RAM and stack space
Directly addressable I/O register space
On-chip nonvolatile Flash data memory
External data memory
On-chip nonvolatile Flash program memory
External program memory
On-chip nonvolatile Flash signature array
38). Constant tables can be allocated within the entire 64K
Figure
3-1.
Prescaler Rate
Compatibility
AUXR
12
2000H–FFFFH (AT89LP51)
1000H–FFFFH (AT89LP52)
0000H–0FFFH (AT89LP51)
0000H–1FFFH (AT89LP52)
AT89LP51/52
Table
0000H–00FFH
0100H–FFFFH
0000H–01FFH
00H–FFH
80H–FFH
00H–7FH
Range
System Clock
3-1.
WDTCON
Fast
2
11