ST72344S4 STMicroelectronics, ST72344S4 Datasheet - Page 28

• Manufacturer Part Number: ST72344S4
• Description: 8-bit MCU
• Manufacturer: STMicroelectronics

Specifications of ST72344S4

• Up To 16 Kbytes Program Memory: single voltage extended Flash (XFlash) with readout and write protection, in-circuit and inapplication programming (ICP and IAP). 10K write/erase cycles guaranteed, data retention
• 256 Bytes Data Eeprom With Readout Protection. 300k Write/erase Cycles Guaranteed, Data Retention: 20 years at 55 °C.
• Clock Sources: crystal/ceramic resonator oscillators, high-accuracy internal RC oscillator or external clock
• 5 Power-saving Modes: Slow, Wait, Halt, Auto-wakeup from Halt and Active-halt
• 16-bit Timer A With: 1 input capture, 1 output compares, external clock input, PWM and pulse generator modes
• 16-bit Timer B With: 2 input captures, 2 output compares, PWM and pulse generator modes

Flash program memory
4.3.1
4.3.2
4.4
Note:
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1
2
In-circuit programming (ICP)
ICP uses a protocol called ICC (in-circuit communication) which allows an ST7 plugged on a
printed circuit board (PCB) to communicate with an external programming device connected
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.
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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).
In-application programming (IAP)
This mode uses an IAP Driver program previously programmed in Sector 0 by the user (in
ICP mode).
This mode is fully controlled by user software. This allows it to be adapted to the user
application, (user-defined strategy for entering programming mode, choice of
communications protocol used to fetch the data to be stored etc.)
IAP 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 programming operation.
ICC interface
ICP needs a minimum of 4 and up to 7 pins to be connected to the programming tool. These
pins are:
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If the ICCCLK or ICCDATA pins are only used as outputs in the application, no signal
isolation is necessary. As soon as the Programming Tool is plugged to the board, even if an
ICC session is not in progress, the ICCCLK and ICCDATA pins are not available for the
application. If they are used as inputs by the application, isolation such as a serial resistor
has to be implemented in case another device forces the signal. Refer to the Programming
Tool documentation for recommended resistor values.
During the ICP session, the programming tool must control the RESET pin. This can lead to
conflicts between the programming tool and the application reset circuit if it drives more than
5 mA at high level (push pull output or pull-up resistor<1K). A schottky diode can be used to
Download ICP Driver code in RAM from the ICCDATA pin
Execute ICP Driver code in RAM to program the Flash memory
RESET: device reset
V
ICCCLK: ICC output serial clock pin
ICCDATA: ICC input serial data pin
ICCSEL: ICC selection
OSC1: main clock input for external source (not required on devices without
OSC1/OSC2 pins)
V
SS
DD
: device power supply ground
: application board power supply (optional, see Note 3)
Doc ID 12321 Rev 5
ST72344xx ST72345xx