AS8267 datasheet(87/136 Pages) AMSCO

87 / 136 page

Data Sheet AS8267 / AS8268

Revision 1.0, 19-Jun-07

Page 87 of 136

Block Diagram

The block diagram shows the main block involved in the security concept.

According to the block diagram there are four possibilities to get access to the internal Flash memory.

Access via UART1

In this mode program/data can be read from or written in the Flash using commands defined in the SCT

(System Control).

Access via SPI_FLASH Interface

In this mode program/data can be read from or written to the Flash using the SPI_Flash interface. This path

also includes a command interpreter which is able to handle different Flash access commands. Please

refer to the SPI section in this document.

To use this mode the SPI interface must be configured as slave (SPI_Flash).

Access via SPI2 Interface

In this mode it is not possible to directly access the Flash memory from extern due to the missing command

interpreter. A direct access to the Flash therefore would only be possible if there would be a program

available in the mcu doing the command interpretation.

Access via UART2

In this mode there is also no command interpreter in the communication path, so that a direct access to

Flash is not possible.

The Flash memory access via UART1 or SPI_Flash interface is an external Flash memory access and therefore

protected by password.

The Flash memory access via SPI2 interface or UART2 interface is an internal Flash memory and therefore not

protected by password. The protection of this path is up to the user.

AS8267 Datasheet(PDF) 87 Page - ams AG