ST72325XXX Datasheet, PDF (34/243 Pages) STMicroelectronics – SCI asynchronous serial interface

Flash program memory
4
Flash program memory
ST72325xxx-Auto
4.1
Introduction
The ST7 dual voltage High Density Flash (HDFlash) is a non-volatile memory that can be
electrically erased as a single block or by individual sectors and programmed on a byte-by-
byte basis using an external V_PP supply.
The HDFlash devices can be programmed and erased off-board (plugged in a programming
tool) or on-board using ICP (in-circuit programming) or IAP (in-application programming).
The array matrix organization allows each sector to be erased and reprogrammed without
affecting other sectors.
4.2
Main features
● 3 Flash programming modes:
) – Insertion in a programming tool. In this mode, all sectors including option bytes
t(s ^{can be programmed or erased.}
c – ICP (in-circuit programming). In this mode, all sectors including option bytes can
u _{be programmed or erased without removing the device from the application board.}
rod – IAP (in-application programming). In this mode, all sectors except Sector 0 can be
programmed or erased without removing the device from the application board
P _{and while the application is running.}
te ● ICT (in-circuit testing) for downloading and executing user application test patterns in
le ^RAM
o _{● Readout protection}
bs _{● Register Access Security System (RASS) to prevent accidental programming or}
O erasing
t(s) ^{- 4.3}
Structure
uc The Flash memory is organized in sectors and can be used for both code and data storage.
rod ^{Depending on the overall Flash memory size in the microcontroller device, there are up to}
three user sectors (see Table 6). Each of these sectors can be erased independently to
P _{avoid unnecessary erasing of the whole Flash memory when only a partial erasing is}
te^required.
Obsole^{Table 6.}
Sectors available in Flash devices
Flash size (bytes)
Available sectors
4K
Sector 0
8K
Sectors 0, 1
> 8K
Sectors 0, 1, 2
The first two sectors have a fixed size of 4 Kbytes (see Figure 6). They are mapped in the
upper part of the ST7 addressing space so the reset and interrupt vectors are located in
Sector 0 (F000h-FFFFh).
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Doc ID 13770 Rev 3