ST7LITE20F2 STMicroelectronics, ST7LITE20F2 Datasheet - Page 13

• Manufacturer Part Number: ST7LITE20F2
• Description: 8-BIT MCU WITH SINGLE VOLTAGE FLASH MEMORY, DATA EEPROM, ADC, TIMERS, SPI
• Manufacturer: STMicroelectronics

Specifications of ST7LITE20F2

• 8 Kbytes Single Voltage Flash Program Memory With Read-out Protection, In-circuit Programming And In-application Programming (icp And Iap). 10k Write/erase Cycles Guaranteed, Data Retention: 20 years at 55˚C.
• Clock Sources: Internal 1% RC oscillator, crystal/ceramic resonator or external clock
• Five Power Saving Modes: Halt, Active-Halt, Wait and Slow, Auto Wake Up From Halt

FLASH PROGRAM MEMORY (Cont’d)
4.4 ICC interface
ICP needs a minimum of 4 and up to 6 pins to be
connected to the programming tool. These pins
are:
Notes:
1. 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 de-
vice forces the signal. Refer to the Programming
Tool documentation for recommended resistor val-
ues.
2. During the ICP session, the programming tool
must control the RESET pin. This can lead to con-
flicts between the programming tool and the appli-
cation reset circuit if it drives more than 5mA at
high level (push pull output or pull-up resistor<1K).
Figure 5. Typical ICC Interface
APPLICATION
POWER SUPPLY
– RESET: device reset
– V
– ICCCLK: ICC output serial clock pin
– ICCDATA: ICC input serial data pin
– CLKIN/PB4: main clock input for external
– V
source
al, see Note 3)
SS
DD
: device power supply ground
: application board power supply (option-
(See Note 3)
OPTIONAL
(See Note 4)
ST7
HE10 CONNECTOR TYPE
10
ICC CONNECTOR
9
PROGRAMMING TOOL
A schottky diode can be used to isolate the appli-
cation RESET circuit in this case. When using a
classical RC network with R>1K or a reset man-
agement IC with open drain output and pull-up re-
sistor>1K, no additional components are needed.
In all cases the user must ensure that no external
reset is generated by the application during the
ICC session.
3. The use of Pin 7 of the ICC connector depends
on the Programming Tool architecture. This pin
must be connected when using most ST Program-
ming Tools (it is used to monitor the application
power supply). Please refer to the Programming
Tool manual.
4. Pin 9 has to be connected to the CLKIN/PB4 pin
of the ST7 when the clock is not available in the
application or if the selected clock option is not
programmed in the option byte. ST7 devices with
multi-oscillator capability need to have OSC1 and
OSC2 grounded in this case.
5. With any programming tool, while the ICP option
is disabled, the external clock has to be provided
on PB4.
Caution: During normal operation the ICCCLK pin
must be pulled- up, internally or externally (exter-
nal pull-up of 10k mandatory in noisy environ-
ment). This is to avoid entering ICC mode unex-
pectedly during a reset. In the application, even if
the pin is configured as output, any reset will put it
back in input pull-up.
7
8
ICC CONNECTOR
5
6
4
3
ICC Cable
1
2
See Note 1 and Caution
APPLICATION BOARD
See Note 2
APPLICATION
RESET SOURCE
APPLICATION
ST7LITE2
I/O
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