Remote Field Updates withh IAPIAP
1. Before IAP
• 8051s typically cannot write to “code” space |
8032 MCU
READ &
WRITE
READ
ONLY
2nd Flash
DATA
MAIN FLASH
OLD
CODE
– Special µPSD register eliminates this limitation | |
• Typical Flash memory cannot be read and written | |
at the same time | |
– | Dual Banks of Flash eliminate this limitation |
– | Read program from one bank while writing to the other bank |
2. During IAP
•MCU reading program from Main Flash
USB, UART,
I2C, Modem…
Updated •
Program •
8032 MCU
READ |
ONLY |
READ & |
WRITE |
2nd Flash
CODE
MAIN FLASH
TREAT AS DATA
•Special Register classifies Main Flash as Code again
•MCU now reading new program from Main Flash
3.After IAP
READ &
WRITE
22ndnd FlashFlash |
Special Register temporarily re- classifies Main Flash as Data
MCU now reads IAP program from 2nd Flash while receiving bytes of new program from USB, UART, Modem, I2C, etc. and writes the new program to Main Flash
8032 MCU
READ ONLY
DATADATA |
MAINMAIN |
FLASHFLASH |
NEWNEW |
CODECODE |
www.st.com/micropsd | 8 |