AT89C5131A-L

Manufacturer Part NumberAT89C5131A-L
ManufacturerAtmel Corporation
AT89C5131A-L datasheets
 

Specifications of AT89C5131A-L

Flash (kbytes)32 KbytesMax. Operating Frequency48 MHz
Cpu8051-12CMax I/o Pins34
Usb Transceiver1Usb SpeedFull Speed
Usb InterfaceDeviceSpi1
Twi (i2c)1Uart1
Sram (kbytes)1.25Eeprom (bytes)1024
Self Program MemoryAPIOperating Voltage (vcc)3.0 to 3.6
Timers4IspUART/USB
WatchdogYes  
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In-Application
The IAP allows to reprogram a microcontroller on-chip Flash memory without removing it from
the system and while the embedded application is running.
Programming/S
The user application can call Application Programming Interface (API) routines allowing IAP.
elf
These API are executed by the bootloader.
Programming
To call the corresponding API, the user must use a set of Flash_api routines which can be linked
with the application.
Example of Flash_api routines are available on the Atmel web site on the software package:
C Flash Drivers for the AT89C5131A for Keil
The flash_api routines on the package work only with the USB bootloader.
The flash_api routines are listed in APPENDIX-B.
API Call
Process
The application selects an API by setting the 4 variables available when the flash_api library is
linked to the application.
These four variables are located in RAM at fixed address:
api_command: 1Ch
api_value: 1Dh
api_dph: 1Eh
api_dpl: 1Fh
All calls are made through a common interface “USER_CALL” at the address FFC0h.
The jump at the USER_CALL must be done by LCALL instruction to be able to comeback in the
application.
Before jump at the USER_CALL, the bit ENBOOT in AUXR1 register must be set.
Constraints
The interrupts are not disabled by the bootloader.
Interrupts must be disabled by user prior to jump to the USER_CALL, then re-enabled when
returning.
Interrupts must also be disabled before accessing EEPROM data then re-enabled after.
The user must take care of hardware watchdog before launching a Flash operation.
For more information regarding the Flash writing time see the AT89C5131A datasheet.
4287E–USB–04/08
AT89C5131A USB Bootloader
®
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