![](http://datasheet.mmic.net.cn/120000/ST7FL19F1MATRE_datasheet_3576789/ST7FL19F1MATRE_10.png)
ST7L15, ST7L19
10/138
4 FLASH PROGRAM MEMORY
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 on-board using
In-Circuit Programming or In-Application Program-
ming.
The array matrix organization allows each sector
to be erased and reprogrammed without affecting
other sectors.
4.2 MAIN FEATURES
■ 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
4.3 PROGRAMMING MODES
The ST7 can be programmed in three different
ways:
– Insertion in a programming tool. In this mode,
Flash sectors 0 and 1, option byte row and
data EEPROM (if present) can be pro-
grammed or erased.
– In-Circuit Programming. In this mode, Flash
sectors 0 and 1, option byte row and data
EEPROM (if present) can be programmed or
erased without removing the device from the
application board.
– In-Application Programming. In this mode,
sector 1 and data EEPROM (if present) can
be programmed or erased without removing
the device from the application board and
while the application is running.
4.3.1 In-Circuit Programming (ICP)
ICP uses a protocol called ICC (In-Circuit Commu-
nication) which allows an ST7 plugged on a print-
ed circuit board (PCB) to communicate with an ex-
ternal programming device connected via a cable.
ICP is performed in three steps:
– Switch the ST7 to ICC mode (In-Circuit Com-
munications). This is done by driving a specif-
ic signal sequence on the ICCCLK/DATA pins
while the RESET pin is pulled low. When the
ST7 enters ICC mode, it fetches a specific RE-
SET 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
Depending on the ICP Driver code downloaded in
RAM, Flash memory programming can be fully
customized (number of bytes to program, program
locations, or selection of the serial communication
interface for downloading).
4.3.2 In-Application Programming (IAP)
This mode uses an IAP Driver program previously
programmed in Sector 0 by the user (in ICP
mode).
IAP mode is fully controlled by user software, al-
lowing it to be adapted to the user application
(such as a user-defined strategy for entering pro-
gramming mode or a choice of communications
protocol used to fetch the data to be stored). This
mode can be used to program any memory areas
except Sector 0, which is write/erase protected to
allow recovery in case errors occur during the pro-
gramming operation.
1