AN2475 datasheet(9/37 Pages) STMICROELECTRONICS

Part #	AN2475

Description	STR91xFAxxx in-application programming using UART

PDF	37 Pages

Scroll/Zoom	100%

Manufacturer	STMICROELECTRONICS [STMicroelectronics]

Direct Link	http://www.st.com

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9 / 37 page

AN2475

IAP using the ST Flash loader

9/37

The figure below shows the IAP flowchart.

Figure 4.

Flowchart of the IAP using the bootloader protocol driver

Once the push button is pressed, the IAP code begins to scan the UART0_RX line, waiting

to receive 0x7F data from the host: one start bit, 0x7F data bits, even parity bit and one stop

bit.

Next, the code initializes the serial interface (115200 bps, Even Parity, One Stop bit). Then,

the STR91xFA returns an acknowledge byte (0x79) to the host, signaling that it received the

0x7F byte and it is ready to receive user commands.

Send ACK byte

Yes

Wait for 0x7F from

the host

Jump to user

program

Initialize the STR9 UART & PLL

Start

ai15301

Wait for a command

GET command

GET ID command

WRITE command

GO command

Push button

pressed

AN2475 Datasheet(PDF) 9 Page - STMicroelectronics