AT89C51AC2 Atmel Corporation, AT89C51AC2 Datasheet - Page 18

• Manufacturer Part Number: AT89C51AC2
• Manufacturer: Atmel Corporation

Specifications of AT89C51AC2

• Flash (kbytes): 32 Kbytes
• Max. Operating Frequency: 40 MHz
• Cpu: 8051-12C
• Max I/o Pins: 34
• Uart: 1
• Adc Channels: 8
• Adc Resolution (bits): 10
• Adc Speed (ksps): 62.5
• Sram (kbytes): 1.25
• Eeprom (bytes): 2048
• Self Program Memory: API
• Operating Voltage (vcc): 3.0 to 5.5
• Timers: 4
• Isp: UART
• Watchdog: Yes

Flow Description
Read Example
Flash Erase
18
A/T89C51AC2 UART Bootloader
COMMAND FINISHED
Wait Value of Data
Send Read Command
OR
Host
OR
COMMAND ABORTED
Wait Checksum Error
COMMAND ABORTED
Wait Security Error
The flow described below allows the user to erase the Flash memory.
Two modes of Flash erasing are possible:
•
•
The Full Chip erase command erases the whole Flash (32 Kbytes) and sets some Configuration
Bytes at their default values:
•
•
•
The full chip erase is always executed whatever the Software Security Byte value is.
Note:
The Block erase command erases only a part of the Flash.
Three Blocks are defined in the A/T89C51AC2:
•
•
Full-chip erase
Block erase
BSB = FFh
SBV = FCh
SSB = FFh (NO_SECURITY)
block0 (From 0000h to 1FFFh)
block1 (From 2000h to 3FFFh)
Take care that the full chip erase execution takes few seconds (256 pages )
Read function (read SBV)
Atmel Read function (read Bootloader version)
HOST
BOOTLOADER
HOST
BOOTLOADER
’value’ & ’.’ & CR & LF
Read Command
’X’ & CR & LF
’L’ & CR & LF
: 02 0000 05 07 02 F0
: 02 0000 05 07 02 F0 Value . CR LF
: 02 0000 01 02 00 FB
: 02 0000 01 02 00 FB Value . CR LF
Send Checksum Error
Send Security Error
Bootloader
Wait Read Command
RD_WR_SECURITY
Send Data Read
Checksum Error
Read Value
4231D–CAN–03/08