AT89C51AC2 Atmel Corporation, AT89C51AC2 Datasheet - Page 20

• 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

Start the Application
Requests from Host
Answer from Bootloader No answer is returned by the device.
Start Application
Example
20
A/T89C51AC2 UART Bootloader
The flow described below allows to start the application directly from the bootloader upon a spe-
cific command reception.
Two options are possible:
•
•
Start the application with a reset pulse generation (using watchdog).
When the device receives this command the watchdog is enabled and the bootloader enters
a waiting loop until the watchdog resets the device.
Take care that if an external reset chip is used the reset pulse in output may be wrong and in
this case the reset sequence is not correctly executed.
Start the application without reset
A jump at the address 0000h is used to start the application without reset.
Start Application with reset pulse
Start Application without reset at address 0000h
HOST
BOOTLOADER
HOST
BOOTLOADER
Start application with a
reset pulse generation
Start application with a
Command Name
jump at “address”
: 02 0000 03 03 00 F8
: 02 0000 03 03 00 F8
: 04 0000 03 03 01 00 00 F5
: 04 0000 03 03 01 00 00 F5
Record
Type
03h
Offset
Load
x
Record
Length
02h
04h
Data[0]
03h
Data[1]
00h
01h
Data[2]
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4231D–CAN–03/08
Address
Data[3]
-