AT89LP428 Atmel Corporation, AT89LP428 Datasheet - Page 9

• Manufacturer Part Number: AT89LP428
• Manufacturer: Atmel Corporation

Specifications of AT89LP428

• Flash (kbytes): 4 Kbytes
• Max. Operating Frequency: 25 MHz
• Cpu: 8051-1C
• Max I/o Pins: 30
• Spi: 1
• Uart: 1
• Sram (kbytes): 0.75
• Eeprom (bytes): 512
• Self Program Memory: IAP
• Operating Voltage (vcc): 2.4 to 5.5
• Timers: 3
• Isp: SPI/OCD
• Watchdog: Yes

3.1
3.1.1
3654A–MICRO–8/09
Program Memory
SIG
Table 3-2.
The AT89LP428/828 contains 4K/8K bytes of on-chip In-System Programmable Flash memory
for program storage. The Flash memory has an endurance of at least 100,000 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
tables can be allocated within the entire 4K/8K program memory address space for access by
the MOVC instruction. The AT89LP428/828 does not support external program memory. A map
of the AT89LP428/828 program memory is shown in
Figure 3-1.
In addition to the 4K/8K code space, the AT89LP428/828 also supports a 128-byte User
Signature Array and a 64-byte Atmel Signature Array that are accessible by the CPU. The Atmel
Signature Array is initialized with the Device ID in the factory. The second page of the User Sig-
nature Array (00C0H - 00FFH) is initialized with analog configuration data including the Internal
RC Oscillator calibration byte. The User Signature Array is also available for user identification
codes or constant parameter data. Data stored in the signature array is not secure. Security bits
will disable writes to the array; however, reads by an external device programmer are always
allowed.
Name
DATA
IDATA
SFR
EDATA
FDATA
CODE
SIG
00FF
0080
003F
0000
0000
0FFF
Atmel Signature Array
User Signature Array
Program Memory
AT89LP828 Memory Address Spaces
Program Memory Map
AT89LP428
Description
Directly addressable internal RAM
Indirectly addressable internal RAM and stack space
Directly addressable I/O register space
On-chip Extra RAM
On-chip nonvolatile Flash data memory
On-chip nonvolatile Flash program memory
On-chip nonvolatile Flash signature array
0080
003F
0000
0000
00FF
1FFF
Figure
Atmel Signature Array
User Signature Array
Program Memory
AT89LP828
3-1.
Table 9-1 on page
AT89LP428/828
0000H - 1FFFH
0000H - 01FFH
0200H - 05FFH
0000H - 00FFH
00H - FFH
80H - FFH
00H - 7FH
30). Constant
Range
SIGEN = 1
SIGEN = 0
9