Flash program memory
4 Flash program memory
ST7LITEU05 ST7LITEU09
4.1 Introduction
The ST7 single voltage extended Flash (XFlash) is a non-volatile memory that can be electrically erased and programmed either on a byte-by-byte basis or up to 32 bytes in parallel.
The XFlash devices can be programmed off-board (plugged in a programming tool) or onboard using in-circuit programming or in-application programming.
The array matrix organization allows each sector to be erased and reprogrammed without affecting other sectors.
• ICP (In-circuit programming)
• IAP (In-application programming)
• ICT (In-circuit testing) for downloading and executing user application test patterns in
RAM
• Sector 0 size configurable by option byte
• Readout and write protection.
The ST7 can be programmed in three different ways:
• Insertion in a programming tool. In this mode, Flash sectors 0 and 1 and option byte row can be programmed or erased.
• In-Circuit Programming. In this mode, Flash sectors 0 and 1 and option byte row can be programmed or erased without removing the device from the application board.
• In-application programming. In this mode, sector 1 can be programmed or erased without removing the device from the application board and while the application is running.
ICP uses a protocol called ICC (in-circuit communication) which allows an ST7 plugged on a
Obsolete Product(s) - Obsolete Product(s) via cable. ICP is performed in three steps:
• Switch the ST7 to ICC mode (in-circuit communications). This is done by driving a specific signal sequence on the ICCCLK/DATA pins while the RESET pin is pulled low.
When the ST7 enters ICC mode, it fetches a specific RESET vector which points to the
ST7 system memory containing the ICC protocol routine. This routine enables the ST7 to receive bytes from the ICC interface.
• Download ICP driver code in RAM from the ICCDATA pin
• Execute ICP driver code in RAM to program the Flash memory
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